Out in February by the looks of it.......the waiting game begins.

UFO: Aftershock and Jagged Alliance 2 with 1.13 patch/mod. Can't get away from either game no matter how hard I try.
A year ago it was the latest installment of Universal Combat called Collector's Edition. Man too much time on that. If you get the controls down you can feel like a captain of a spaceship for real, nothing like it.

Woot! Another Universal Combat lover!

Hmm. I usually tire of single player games after a while, regardless of how addictive they are.
I believe 110 hours with FFXII means it qualifies as "slightly obsessed on", but my characters are still only level 45, and I've got most of the optional end-game left to do. It will probably be tricky, too, considering I'm running out of stuff I can do at this level. Guess I need some more of those experience boosting accessories.
A more likely contender for me is Braid. By comparison I've only spent 30.6 hours with it, but remember that your first run usually only takes about three or four hours, tops. I've gotten every Steam Achievement (well, only one of them is prestigious) and the hidden ending, and run through the game... loads of times.
Cave Story doesn't really qualify - even though I've played through it countless times, it's often been to fill, say, bus rides, long breaks or boring classes. I regret nothing, however.
Now, Final Fantasy Tactics Advance: here's a real contender. I played through it once, and at around 80 hours /played (I think) I realised I shouldn't've chucked that Black Thread earlier. I restarted the game and spent another 70 or 80 hours doing it right this time, eventually getting 100% completed. I really should pick up #2 one of these days.
There's also been a bunch of games I've played for longer than I should have thanks to challenge modes, Achievements or both. Arkham Asylum comes to mind, with 30 hours of /played time and only two Achievements missing.
Mulling over the candidates, I think I'll declare it a 3-way tie between FFXII, FFTA and Braid. I'm done with Braid and FFTA, but I felt I got a lot more fun out of them than I should have, and FFXII, well, maybe I'll go for the 12-hour boss, maybe I won't. But it's just a brilliant game that's difficult to let go.

Duke Nukem 3D
....No Questions....

The fact that you bought a 360 just for some shitty Wing game on the XBLA means you are truly dedicated.

I'm obsessed with kotor. bioware + star wars = epic win

I can't beat Vagabond unfortunately, but here's my most extreme obsession.

It was quite a decision. Here's the page in the game's manual where I am. Truly honored they recognized me.

Yeah, you know, games are great and all, and there's some truly amazing stuff to play. But... Fanboy-ism is not healthy, makes you do crazy things and later you're spending your whole time rationalizing it. I like the non-computer part of my life too.
In short, I don't think there's any game one couldn't live without.

well i think that fanboyism can sometimes be a good thing in a persons life. some people are weird and don't fit and wouldn't have any friends if they weren't united by there fanaticism for a game or TV show.

I love the Ace Attorney series as well, but I don't really have much to show for it... just the games, the OBJECTION! stylus, and I have that shitty Phoenix doll hanging from the mirror in my car.

For me, it's The Chronicles of Riddick. God knows how much I love that game. I mean, there are other games I love equally as much, like the classic Doom, or Planescape Torment, or System Shock 2, or Deus Ex, but I had to mention Chronicles of Riddick because it takes the cake in that it's simply one of the most underrated, unheard of FPSes, despite the fact that it did nearly everything right I.M.O