Yup. Arcanum has terrible combat. Still love the game for everything else though,

Deus Ex didn't had good combat because of the stats were poorly calibrated, the game doesn't use dice rolls for the shooting, it just keep the inaccuracy state for too long and each time you upgrade your weapons the necessary aiming time to reach accuracy is shorter and weapon damage increases.
Other than that with a few tweaks the game could have been good even at on this specific area
Damage scale, recoil, crosshair shrink and expand and overall weapons stats if they are changed in the right way, you can have good combat.
Games like fallout 3 have more of the rolling dice in combat than Deus Ex

Would you consider Demon's Souls an example of #3? I never got far enough to see the difference between the later levels and the bosses. Not out of difficulty, just eventually moved on.

Dragon Age 2's first boss fully justifies point number 3

I'd say my experience with Arcanum was more complicated. I usually found that I could roll with the turn-based combat if I approached it a certain way; it was more when you combine that style of combat with the problematic false build syndrome that I wound up getting exhausted with it...  At times though I really felt like I was just clicking away to expend my AP. 

Makes me want another Wizardry or Might and Magic style multi-member party with static tactical choices, even if that's not everybody's bag. That way you get a lot more choices rather than a few, and can concentrate on how those all interrelate.  X-Com had an AP system and felt a lot more tense and dynamic, even though there weren't too many more options. A lot of that had to do with facing and alertness. I wonder if there's something to that that could be exploited down the road by RPG makers, especially since things are going a bit too far in the FFT direction at times.

I would like to submit enemies that are premanently immune to certain damage types for your consideration. The most obvious example being Diablo II, where characters that deal fire damage basically can't play on Hell difficulty and have to rely on other players for 90% of the time. 

" @GunslingerPanda:  I'm sorry. I just assumed you were talking about Dragon Age 2 because that's the cool thing to hate these days. If not that, what were you talking about? . "

" @GunslingerPanda:  I think the correct term would be: Force your team onto an 18 month dev cycle to make a 30+ hour game, but more or less same difference. Of course, let's pretend you're not talking about Dragon Age 2 or what have you, do you have any other examples of RPG sequels that suffered from their new corporate masters?  "

Dave all but suplexed that train Sabin-style in that Railworks QL.

Combat's definitely a tricky thing to get right in any kind of RPG. The biggest hurdle for designers is not only creating encounters that require some contemplation from the player beyond "mash the mouse button until all the bad things go away", but to repeatedly do so for the length of the game. It's something that only gets trickier as you get close to the end and the player has evolved their characters in any one of a hundred different directions (depending on the complexity of the character development, of course). I try and keep that in mind if the difficulty curve has gone all screwy on me.

For me personally the biggest crime is making your combat system boring. Invisible dice rolls and "that one boss" are omnipresent issues in most RPGs that should really be phased out, but overall they're not dealbreakers. If the combat's boring (re: your second section), though, I think that's probably a death knell. That and maze-like dungeons with no maps and constant random encounters. I hate those. Cover those next.

Train simulations have no bosses? I beg to disagree:

  

How to make a bad RPG: Get bought by EA.

at least a few of AP's bosses can be cheesed: if you run around the center of the stage, he'll never catch up with you.

Blatant Dice Rolls in something that looks like it shouldn't have dice rolls (Or: If it looks like a duck syndrome.)

This is a problem that really, really irks me. I know RPGs are about progression, but nothing kills my suspension of disbelief like aiming straight for a dude's head with a pistol and missing. While I'm not going to say that every "Action" RPG deserves this derision (The problems with Fallout 3 and New Vegas' combat has very little to do with the occasional missed shot at long range) I am going to complain about the ones that make it blatant for all to see that your skill as a human being has very little to do with it and it's all about how many points you put into whatever, especially if you have to put a lot of points into it. This is very much a sin of degrees, especially regarding the context in which the combat scenarios occur. How accurate are the guns themselves? Do I have to stand still or something in order to get a “Critical Hit”? How many people do I have to murder during the course of the game? All these are questions one must ask in this regard. Example: Deus Ex

A sterling example if ever I saw one. While I'm not deriding Deus Ex at all (in fact, I think it's pretty good so far, this obvious flaw notwithstanding) I do have issue with the way it handles the shooting. Alpha Protocol had a similar problem, and I'm sure I've made my opinion on that game clear. Clearly, Deus Ex is trying to be an RPG first and all that, but does that mean that I can't hit the broadside of a barn unless I stand totally still for 5 seconds or put all my points in weapon skills? As a super nano-agent with the most hilariously monotone voice ever, shouldn't J.C. Denton be able to hold his sniper rifle still for just a second? It's good that the game offers other avenues for the player to go through, but the second I'm forced into combat I'm less than cool with whatever is going on. It doesn't help that the game is so stingy with it's experience points, handing them out 50 to 100 at a time while the next rank in rifles is about 1600 more than you have at the moment. Nonetheless, as long as the game continues going the way it is, and doesn't do anything really stupid you can expect to hear more from me about it in the future.

Unstrategic Strategic Combat

On a similar note, while obvious dice rolls are the bane of action RPGs, these are the bane of traditional ones. It's fairly simple: If the game gives the illusion of requiring thought from the player, but instead just leads to a Diablo style clickfest (but without the viscerial appeal or quick thinking required of Diablo. Don't believe me? Try going back to Diablo 1. Now try not to die. Hard, right?) This is usually more of a problem when there is only one player created character, and while I still think there's some strategy to be had in regards to stuff like fallout (but really, let's be fair: Fallout's combat isn't that strategic, but at least you can shoot people in the balls. Fallout Tactics probably is strategic.) these games are clearly just an issue of being a high enough level or being lucky enough to have the dice rolls go your way.

Example: Arcanum

Boss Battles that are exponentially harder than anything else in the game

Example: Alpha Protocol