What's your most played game this generation?

GTA IV, followed by CoD4 and New Vegas.

Resistance 2 for sure..lot of playthroughs and a lot of online time. Uncharted 2 is close behind

" Left 4 Dead (360): 207 Hours

Notable mentions:

BF1943 (XBLA): 110 Hours (and still playing)

The Last Remnant: 101 Hours (why did I do that to myself?)

Starcraft 2: LOTS

"

Warcraft - for obvious reasons
Live for speed
Fable 3

Gears 1 and Resident Evil 5.

" Burnout Paradise i had like 200 hours... Bad Company 2 i have 104 hours in... "

Probably SSFIV. I love it so much. It has a ton of characters to learn and they all feel unique. It's also responsible for getting me back into fighting games.

It'll be on Rock Band. I dread to think how many hours we've pumped into that series.

World of Warcraft - I finally stopped playing months ago, but the last time I checked I was around 128 days played.

Halo 3

Its going to be New Vegas at my rate.

Crazy amounts of time in Oblivion.

Over 1000 hours logged in Guild Wars, and counting.

Mass Effect - 7 playthroughs totaling about 120 hours

Fallout 3 - 2 playthroughs including DLC totaling about 100 hours

Call of Duty 4 - 100 hours or so online + two campaign playthroughs

Rock Band (1, 2 and 3) - Many countless hours...has gotta be at least 100

Probably Halo 3 multiplayer.

battlefield 2... i don't even want to know how much time I put into that

Mass Effect 2, Fallout 3, Blazblue, MW2, and WoW. (>.>)

Team Fortress 2 with about 2088 hours right now. 
I ain't gonna stop anytime soon too!

CoD4. I had a ridiculous amount of time logged into that mp.

Does handhelds count?

Fallout 3. Definitely. I still need to put another 200 or so hours into it too.

L4D hands down. Me and my friend still play that on a regular basis. No solid numbers to give you, though. 

I just keep replaying Half Life -HL2 -Ep1-Ep2 Over..and over...and over *bleary eyed expression*

Team Fortress 2 and Oblivion.

Dawn of War 2(plus expansions) - 650h and counting
Guild Wars (plus expansions) - 600h
Heroes of Newerth - 440h
Dragon Age:Origins - 204h

I have about 4500 hours in World of Warcraft. I've been playing since launch though, so this is over the course of a little bit more then 6 1/2 years.

Ninja Gaiden 2 or the first Gears of War. 

Warhawk.  I think I played that game for around a half of a year.

S/SF4 easily.

Dunno if this counts but I have over 300 hours clocked in M&B warband...

Other than that I guess it would be Demons Souls.

Definitely Fallout 3.

Gears of war 2 according to my stats page 
 14 day(s), 03:05:42

<ouch!>  (and i STILL dont have seriously 2.0  but i am not far off now)

in (distant) 2nd place it must be either Forza 3 or DiRT2 (DiRT2 spread over 2 platforms Xbox and PC)

World of Warcraft (dude, no fucking idea how many hours), then Diablo II (again, no idea, played that game almost exclusively from 2002-2008), then Team Fortress 2 (Steam says 600 hours, plus the 150-200 that I'd put in before they added time tracking).

Civ 4.

" World of Warcraft (dude, no fucking idea how many hours), then Diablo II (again, no idea, played that game almost exclusively from 2002-2008), then Team Fortress 2 (Steam says 600 hours, plus the 150-200 that I'd put in before they added time tracking). "

On CoD4 I have around 23 days played of multiplayer. I've also beaten every mission about 20 times (including veteran difficulty). That's a shitton of time played. 

Metal Gear Online. 

Call of Duty 4. About 40 days played over 2 years. 

Tekken 6 by far. it tells me 200+ hours but something is weird about it. i'll play the game for 5+ hours and it adds like an hour at the most. i would say it doesn't count time in menus but it doesn't take THAT long to find a match

SFIV / SSFIV

Easily over 1000 hours