Yes, I know that this has probably been done many, many times before, but now, the game has been out for over a month now, and many players have probably learnt the all the maps by now. So, I made my decision yesterday.
 
Best Maps
 
1. Terminal 
 
This is a fantastic map which is great for any game mode. Domination and Demolition work really well here. The plane and the top of the stairs in the Terminal are great spots to shoot from, and the glass roof of the terminal means that you can drop care packages through the roof. This map is my personal favourite.
 
2. Highrise
 
This map situated on top of a skyscraper is tricky to traverse, but a lot of fun. The 2 opposing sides, the 3 open straights, and the multiple levels make this a great map. Also, there is a crane that you can climb on. Yes. 
 
3. Favela
 
Narrow streets and wide open areas are combined in the map to make something quite special. This map has lots of vertical gameplay, with accessible roofs and balconies. Expect hectic TDM's and Domination games.
 
 
Worst Maps
 
1. Underpass
 
I cannot stress enough how much I hate this map. The rain and the darkness makes everything so difficult. Some players, yes, have got used to it, but I don't think I ever will. 
 
2. Derail
 
This map is too large, and the buildings are oddly placed. Also, it has some of most annoyingly placed demoltion bomb sites.
 
3. Sub Base
 
When I played this map, I expected more of it to be accessible, but its not. This map isn't bad, it just could have been a lot better.

I loves me some terminal.
 
Oh, and Estate.

Terminal
Scrapyard
Afghan
Sub Base
Highrise
Underpass
Estate
Derail
Invasion
Karachi 
Quarry
Wasteland
Rundown
Skidrow
Rust
Favela
 
Listed from favorite to least favorite.

There is no one map for me sadly in this game there are only a few which completely suck and the others do their job.

Terminal, sub base and invasion are my favourite.

Karachi is win.

Put wasteland at 2 and you've got my list.

I enjoy Terminal, Highrise, Favela and Scrapyard.  I'm starting to enjoy Wasteland, Estate, Afghan, Underpass and Skidrow.  I hate Derail (good thing it's not included in FFA), Sub Base and Quarry.

terminal is an amazing map 
 
why it doesnt come up as often as shitty derail is beyond me

Estate, Derail, and Underpass have to be my most hated maps. 
 
Derail is too large, as you said and it is impossible to get anywhere with the safety of cover as there are numerous wide open fields between destinations. Combine snipers in rooftops and forests and this easily tops my list as most hated.
 
Estate has a similar size problem as well as uneven team positions. The house has an almost unfair view of the majority of the map making it difficult to scale the hill without a well organized team or just several skilled players happening to team up for a few seconds. 
 
Underpass is way too dark and grimy for my liking. It's hard to see anything and the center of the map might as well be a pit of lava for how often you'll die once you even set foot on the bridge leading to it.

I love Favela....Dont like Derail...

Get in there! I'm on my favourite, Terminal, now. Oh yeah, about wasteland, it's alright, as long as you stay in or near the bunker, then its hectic.

Show some more love for Sub Base. Since i only play HQ its a pretty awesome map. Unlike scrapyard which is just a gorefest.

I like Scrapyard, Quarry and Terminal. I don't really like playing on Underpass and Karachi that much.

OMG I just got the most badass kill ever on Terminal, I was on top of the stairs inside the building, I jumped off, and using the SPAS-12 shotgun, managed to kill 3 people with one shot while in midair!

Like 
Scrapyard 
Favela 
Highrise 
Afghan 
 
Dislike 
Wasteland 
Quarry 
 
Strongly Dislike 
Rust 
 
Rust is pretty much the worst map ever. Every time I play that map, I spawn and am killed within a half second. One game I came in part way through, played for about 35 seconds, and had 27 deaths and 1 kill. I want to stress that I don't suck at the game, I just get killed instantly.

yeah rust is awful, also criticising sub base for not being as open as you thought it would be is silly, all the city maps have blocked off doors and you can only go in a few buildings. I rreally like all the city levels; invasion, the farm one with the river running through it, the level with the embassy one side and the gas station on the other.. fun
 
also i actually really like derail, it's the only map i snipe on and you can get some good snipe battles going across the map.

" Show some more love for Sub Base. Since i only play HQ its a pretty awesome map. Unlike scrapyard which is just a gorefest. "

I love Terminal. I rarely meet campers, and if I do, they're always in the plane. And that can be fixed with a silenced SMG and some stealthing ;)
 
My top three:
 
Terminal
Sub Base
Derail

Love: Highrise,  Favela
 
Hate: Estate, Skidrow.

Rundown is probably my most hated map in this game.

Am i the only one who hates Terminal?

Skidrow  
Estate
Scrapyard
Favela
Karachi
Highrise 
Derail
Terminal   
Invasion
Quarry
Sub Base 
Afghan
Rundown
Rust
Wasteland 
Underpass
 
 
Underpass is beyond retarded. Maybe it is because I enjoy CQC (which is obvious with Skidrow, Favela, Estate, and Scrapyard all high on my list while large open maps like Wasteland are horrible)

" Yes, I know that this has probably been done many, many times before, but now, the game has been out for over a month now, and many players have probably learnt the all the maps by now. So, I made my decision yesterday.  Best Maps  1. Terminal   This is a fantastic map which is great for any game mode. Domination and Demolition work really well here. The plane and the top of the stairs in the Terminal are great spots to shoot from, and the glass roof of the terminal means that you can drop care packages through the roof. This map is my personal favourite.  2. Highrise  This map situated on top of a skyscraper is tricky to traverse, but a lot of fun. The 2 opposing sides, the 3 open straights, and the multiple levels make this a great map. Also, there is a crane that you can climb on. Yes.   3. Favela  Narrow streets and wide open areas are combined in the map to make something quite special. This map has lots of vertical gameplay, with accessible roofs and balconies. Expect hectic TDM's and Domination games.   Worst Maps  1. Underpass  I cannot stress enough how much I hate this map. The rain and the darkness makes everything so difficult. Some players, yes, have got used to it, but I don't think I ever will.   2. Derail  This map is too large, and the buildings are oddly placed. Also, it has some of most annoyingly placed demoltion bomb sites.  3. Sub Base  When I played this map, I expected more of it to be accessible, but its not. This map isn't bad, it just could have been a lot better. "

 
Wasteland and Quarry are awesome. 
 
Rundown is dumb beyond words.

yuck, Terminal is my least favorite. i feel like im running in a big circle the entire time and people ALWAYS spawn behind you. 

Highrise
Terminal
Invasion
Karachi
Skidrow
Quarry 
Underpass
Sub Base
Estate
Derail
Rundown
Favela
Rust
Wasteland
Afghan
Scrapyard 
 
Why I put Scrapyard last - Yes, something can be said that it is an "Anti-camping" map. But, it does not give you any time to breathe, and even simply reloading is enough time for you to be flanked and killed. It just feels that there are too many side-flank areas on this map. 
 
Why I put Highrise first - This level (along with Terminal) is great for just about any game mode. This feels like the boat from COD4, but refined. The under-areas are great, and make it so that the buildings aren't just super-snipe zones. There are also some really well done spots on this map that really makes it dynamic.

I enjoy Terminal a lot, but I think, objectively, that map has some issues. If a team in Team Deathmatch hunkers down in the corner opposite the baggage and maintenance building, then they can basically control the tone and rhythm of the match.

Sub Base might be my favorite map. That or Scrapyard. Both maps have a nice pace to them, what with their being medium-sized and all. And I feel aware of my surroundings most on those two.  
 
As for dislikes, I've found myself disliking something about almost every map in this game, but Derail has to be, as far as I can remember, the worst map I've ever seen in a first-person shooter.

Skidrow playing domination. The battles at the B flag can get insane

Honestly, Derailed is not a bad level. The only knock I can find on it is its size. But gamemodes that force the players to a certain place (Headquarters comes to mind) show that the map is well-made.
 
Playing new game modes on a map can really change your perspective on it.

Like: Terminal, Afghan
Dislike: Everything else

I don't like any of the town ones: Skidrow, Karachi, Invasion
 
I do like Underpass for the sole reason that everyone and their mother is awful at that map, and I enjoy hiding in the tall grass and popping fools off one by one :D

I pretty much enjoy all the maps.. Each is more diverse then the other.

Best:
1. Terminal
2. Invasion
3. Afghan
 
Worst:
1. Karachi
2. Highrise
3. Rundown
 
(both lists in descending order)
 
I used to hate Favela with a pure, unmitigated, quit-the-game-when-it-appears passion. That was until I discovered that the First Recon default class has the tactical knife setup. Now I have something to survive with it ain't quite as bad. Rundown is camp city, and not even in a good way like you could argue with Wasteland. Karachi is just a travesty of a map, I'm not sure how it passed QC with such an utterly bizarre layout. Highrise offers no opportunities to flank and is therefore just a twitch-trigger contest.
 
I should add that I primarily play Headquarters, so I have different priorities in a map than TDM players. It also means that Underpass is rendered slightly more fun and I never have to play Rust :P

worst map is underpass without a doubt

Best maps MW1
Worst Maps MW2
 
 
They are just boring and camp happy..... tough i do like camping the Burger Town in Terminal
 
Wasteland is a nightmare...but If you play pro versions of Marathon, Lightweight  & Ninja and run around stabbing campers it's fun.

I love Skidrow but the one thing that drives me insane is when I call in a chopper gunner and the entire enemy team is inside. >_<

Rust is my favorite it's so small and flat out crazy

Good Maps:
.....
 
Bad Maps: 
Skidrow
Estate
Scapyard
Favela
Karachi
Highrise
Derail
Therminal
Invasion
Quarry
Sub Base
Afghan
Rundown
Rust
Wasteland
Underpass

Hate wasteland
love Terminal

Best:
1. Favela
2. Terminal
3. Highrise
 

Worst:
1. Estate
2. Wasteland
3. Karachi