I'm going to make sure that this post is relatively spoiler-free, other than text clearly marked with spoiler tags.  It would be nice if everyone's replies did the same, but I can't make any promises. 
 
Anyhow,  I felt LA Noire is one of the most disappointing games that I've played in this console generation. The level of true interactivity in this game is nothing short of shameful. To call this a "detective" game also sort of suggests that you'll actually be "solving" cases by figuring out who is guilty and who is innocent. For the vast majority of the game, nothing could be further from the truth.   
 
Even if you can accept that fact, there are some serious issues with this game, many of which are fantastically detailed in three articles that you can find here:  http://www.gamecritics.com/daniel-weissenberger/la-noire-has-problems  (all sorts of spoilers at that link, of course) 
 
Now, some of it can be a little nit-picky, but there are some huge faults pointed out about this game that I don't feel can be easily defended.  I'll share some of my favorites, and then a couple of my own experiences that weren't even listed. 
  

I'm betting the developers needed to do more homework. (Vice Spoilers) 
 

I actually loved LA Noire, but it wasn't the GOTY I thought it would be. So yes, a little disappointed.

I loved LA Noire. It turned out a lot better then I was expecting as well. I guess I was one of the few people not massively hyped for it though.

no. i wasn't massively disappointed because i aways go into a game with managed expectations. i don't expect from a game i just try to enjoy what the game has too offer. 
 
did i enjoy LA Noir not really i felt it was a little too long in the middle. but i wasn't massively dissapointed

I really disliked L.A. Noir.  I think a lot of people have been charmed by it and they fail to see the games MANY negative points.  The Investigations are mared by bad designer choices (letting the player know they made a wrong choice but not let them do anything about it), a predictable story that tries far too hard in some spots but not hard enough in others and terrible driving mechanics that take any joy away from doing side missions (skipped driving, forced to avoid them) and taking the fun out of some of the cases.
 
The game does have some good things, the face capture is awesome, the game looks great, the world is fully authentic and it has a nice charm to it...but these can't make up for the fact that as a game and/or way to tell a story, it fails pretty darn hard.

LA Noire was fun in the beginning...then I stopped playing about halfway through vice, and I will probably never finish it. It's a good game but after 12-15 hours of gameplay I felt I had seen everything it had to offer.

I really haven't finished it yet, but my takeaway from it at this point is that it's the perfect game critic's game. It appeals to reviewers perfectly. It's a relatively succinct experience. You just sort of coast along so it's not very difficult. And all along it's wowing you with really amazing facial animation tech. But when you boil it down to it's base elements, what you end up with is a pretty simplistic game that isn't actually very fun to play for long periods of time because it's pretty repetitive and basically just does one thing over and over again and is impossible to lose unless you're a complete moron, and even then you still pass cases.
 
It's just one of those games where there's a huge disconnect between what your normal average gameplayer (who, granted, values good gameplay) values, and what a game reviewer values and appreciates. It's perfect for critics.

Yes. There were quite a few threads popping up about it when it first came out expressing dissenting opinion, and I even wrote a negative user review that got a surprising amount of attention.

It's probably my disappointment of the year. It's just so repetitive.I feel like it's a step back from Police Quest

This thread is making me cum. Mentally.
 
Seriously.
 
Critical independent thought going against the grain everywhere.
 
I feel lightheaded.

The only things that I was disappointed about were the ending and the fact that innocent people run away from the police.

I'm pretty disappointed with it. It was my most anticipated game of the year. I thought it would easily be the best GOTY, but it's not. The truth is, the gameplay just isn't very good. You really don't feel like a detective, and like you said, the level of interactivity just isn't very good. With that said, I think it has a lot going for it, but the gameplay just continuously falters. The driving sucks and there's too much of it. The game holds your hand way too much with crime scenes, and when questioning suspects I find it to often be difficult to get across what you're trying to say. The game had great potential, but it fell completely short of it.

In some sense I was satisfied by the game. I thought the interrogations were interesting, even if they were a bit shallow. I didn't find anything horribly repetitive about the game while playing it (save for the silly chase scenes) and saw a lot of potential in the gameplay if they worked a bit at it in future installments in what seems likely to become a franchise.
 
On the other hand, you're absolutely right about the story. One common complaint about the game is that it's clear they spent a great deal of time on the open world itself. The city looks great. Yet it's empty. It's a fantastic setting with nothing much to do. It's obvious that the wrong priorities drove the game development. And the big loser here is the story. It's blatant rip-off of LA Confidential might have been forgivable if they'd actually turned it into a decent story. Games have ripped off far less worthy sources in the past. But the story is utter shit. It often makes no sense. The internal contradictions are distracting. The bit with the wife was so out of left field that I thought I must have missed something.
 
So, yes, disappointed. And yet I still enjoyed the game. Now, given that I had reasonably high hopes for both GTAIV and Red Dead Redemption and was disappointed in many ways by both of them as well, this shouldn't surprise me. But in the scale of Rockstar disappointments, I'd say that LA Noire was somewhat more disappointing than the others. Not disappointed enough for me to outright dislike the game, but disappointed in that I'm a bit sad that the developers missed such a great opportunity to present a unique, engaging story with unique gameplay elements. They only partially delivered on their promises.

More than any other game, I felt like I was just coasting between cutscenes with relatively little agency over the motion of the plot. I didn't expect to have any real control over the destiny of these characters, but there exists a sense--perhaps motivated and reinforced by the dynamic "choose your own adventure" dialogue trees--that I as a player should have more impact on this gamespace than what is actually being demonstrated.  

 L.A. Noire did pretty much exactly what I'd hoped it wouldn't do. I was fine with the idea of a greater arc serving as an umbrella under which the entirety (or majority, rather) of the story operated. But it avoided like a plague giving me isolated, Law and Order-style cases that were mysteries unto themselves. I can't simply go into any one particular case and enjoy the threads of it as a self-contained vignette. Instead, I have to deal with the loose ends that invariably perpetuate after the case has been "solved" so that the game can fuel a narrative I have no vested interest in or direct engagement with. 

I was disappointed because i suffered from the overheating problem, which caused my game to be unplayable, and actually broke my PS3! I have a new one now, and i`m afraid to play it again encase it happens a second time! Other than that, i really liked the game.

No, it was amazing.

Yes, I was very disappointed.

Haven't finished it yet; I dunno why but Rockstar's games feel slightly boring to me when played in longer sessions (had the same problem with RDR, never finished it). Maybe it's the slow pacing or clunky controls. But I intend to get it finished by the end of the summer.
 
I must admit it wasn't really what I had expected. Coming from an Ace Attorney fan I feel like all the interviews are too easy and the evidence connections are either way too obvious or don't really make sense.

No, I really liked it. Also I don't remember the paedophile bit, when the hell was that?

Haven't finished it yet, but so far I'm quite happy with the game.

No, I really liked it. Also I don't remember the paedophile bit, when the hell was that?

 
It was a great game, i played through the whole thing almost twice, but it gets a little repetitive after a while. Even though it does most things well.

No wasn't disappointment at all. Great to have a game from the police end, even if it takes place 1940's.

I am just disappointed because the interrogations can be confusing to say the least sometimes... Then about Cole: I liked him as shallow of a character he was but was really disappointed by his actions later on in the storyline (can´t get the damn spoiler tag to work) 

Also I didn´t like the fact that I took so damn long for the story to pick up steam. Nothing basically happened until the vice desk which is over halfway through the game. 
And the ending, oh the ending... I know it´s a noire ending and all but could they have not done anything better or not out of the blue?  Could have been tied in with the people  involved in the end a lot better.
  

Nonetheless can´t wait for L.A. Noire 2 as I just loved the artstyle and that goes a long way for me...

@SpaceInsomniac: I agree with pretty much everything you said except the pedophile bit.

I feel it is fairly established that neither Jack nor Cole will kill a man in cold blood. Their acts of violence are always initiated as a counter to an existing threat. For example when Jack gets to Leland Monroe, an equally abominable man, he "just" shoots him in the leg.

I agree with the OP; could have been a great game, but was ruined with some silly writing decisions.
 
I kept hearing how the game got so much better after the Homicide missions, but I found the Arson and Ad Vice cases weak. IMO, the final Homicide case was the best of the whole game, and at that point I was sucked in and looked forward to the rest... only to be shattered and disappointed at the average, boring cases that followed. It's like the crescendo came early, and from that point, fell swiftly down. 
 
So yes, I was disappointed.

hugely dissapointed, i traded it in after 4 hours.

Absolutely. I expected a traditional, well done adventure game with a stylish, gritty atmosphere, fantastic acting and a neat interrogation system. What I got was a glorified photo hunt and an half-assed series of quizzes that give you the same three response options for every single question in the entire game. Not good at all.

I'm loving it.

Im struggling to want to finish this game because of the repetitiveness but i know i need to complete it

I finished it and loved it, even though I understand your complaints. Maybe I just like bad games.

It was okay, but I definitely shouldn't have bought it day 1. Especially now that I know of the Team Bondi development situation. Oh well, live and learn.

Yes, yes i was...until i heard on this very forum that it's coming out on PC. Due to the 40's setting and atmosphere (Love that era in American history) I'm pretty sure it will make it to my list of favorite games.

I thought the core gameplay and individual cases were enjoyable, but everything seemed to fall apart in Arson when the game started focusing on the overarching storyline, which I felt was one of the weakest aspects of the game. 

Playing it just made me want a phoenix wright type game with the facial animation + evidence to be brought up during the case and maybe some miles edgeworth type scene investigation.

I pretty much agree with the OP's contention in spoiler#1, and understand the contention and somewhat agree in Spoiler#3 Spoiler #1 is self explanatory. Spoiler#3; I'm sure that it wasn't supposed to be found. Should not have been made..yeah. Also I found the shooting uninspired, and a couple of the characters a bit too close in build and broad general personality (though not on the defining particulars) Just the same, this game rocked. I find the other spoilers the OP's take, and opinions of what he/she likes or dislikes. The story progresses and shows some great nuance of characters outside of the same ole good guy/bad guy bs. Phelps is a flawed individual, and they are all obviously human. This and Vice City(nearly,game hitch near the end) has been the only Rockstar games I have finished. But this one was unique, and that probably reflected the outside developer.

There were some very well made points in the spoilers, I have to say. However, the final one I have to oppose slightly. If you actually complete that scene, you can shoot the guy driving the bulldozer, before you climb out of the trench. Also, there was no reason to shoot at him during the mission: I completed that scene without even pulling the trigger on the bulldozer. Just two little things, but all in all, you made some excellent points.

Watchin Faces! Solvin Cases! - I didn't care for it- but I only played it for 2 hours. Main character had mental problems if his interrogations were anything to go by.

Didn't care for it at all. That is not to say it's a bad game, just was too slow for this GTA infused brain. I beat it and felt like much time was wasted for nothing.

Loved every minute of it. One of the top few games this year.

I was a little disappointed, but I wasn't expecting anything truly spectacular going in. The repetitive structure and the lack of activity in the sand box were the two things that let it down the most, but I still enjoyed my time with it.

I was disappointed with the lack of...well anything in the game really. I thought the first few cases were well put together, Homicide being the pinnacle of excellence, and the fact that I wanted to use my own perception skills made the game fun. But then the cases became pointless, they chucked in a story out of nowhere, and the overall interrogation design was poorly put together. The facial animations were great, but they didn't really matter, because anyone who was lying just looked away...yeah, great tell there, didn't see that coming...but I digress, it was an average game, but the amount of blind, over-hype related backing that this game got just leaves a sour taste in my mouth. 
 
...That and the several dodgy camera angles, the awful driving mechanics and the scale and period model of LA that was criminally underused, the pacing issues, the story issues, the character development issues, the Doubt and Lie options pushing me into rather rash accusations...christ, you know what, I'm not even going to be nice about this game anymore: I played the entire thing, within two weeks, and I felt physically drained after every case. I would have finished it sooner, but I stopped playing it, and might have never gone back if I didn't force myself into thinking that this game was totally going to be worth the money, time and effort that I put into it. But no, I get an ending that makes no sense, a game that feels half made, and a nice gap in my wallet that I could have used for a game that, while not being as interesting conceptually, would have actually delivered on what it was promising.
 
*breathes*...so yes, in summary...disappointed...which may not even cover it...

Overall i dont think its was that great of a game.  It was about a 7.  Story sucked.  Cases really gave you no sense of connection to them. The were some odd plot holes or at least really poor closure in several cases, mostly the Daliah murders. 
 
I also kinda hate the game for the stupid hype over the facial animations.  Its so overblown. i saw one article about how gaming would never be the same.  FUCK YOU!  Did you really have that much of a prob believing or identifying with game characters? 
 
Makes me picture some guy playing Mario.  HAPPY as shit, jumping around, stomping turtles, "OMG this game is so AWESOME"....Then cut scene, "Its'a me!  Mario!"   
 
Guy LOSES his shit!  "FUCK YOU!  Its FAKE, its so FAKE!!!  You fucking LIAR!  I dont believe you!  ITS SO FAKE!!!!

No, I loved every minute of it.

@DillonWerner said:

No, I loved every minute of it.

Seconded. I see how people have issues with it on some levels but it just came together so nicely for me as an interactive aesthetic experience that is hard to put my finger on, and I did feel involved and rewarded when nailing interrogations because I also knew this meant more subtext and nuance to the plot.

I've been know as one of those who deeply disliked this game. Should've gone with my guts and not had listened to Brad's praises for this utter garbage.

No, I loved every minute of it.

im liking it. im playing a case every time i feel the urge and its working well. dont think id want to blaze through the game but i overall like the experience but i can see how some might not.