Call of Duty World at War, first online game i went competitive with, so became addicted and not knowing that there is anything better i pumped 500 hours over a 10 month period.

Wow, it must be painful when you realized that game is a piece of shit.

actually it wasn't that bad, the game that was a piece of shit how ever was Modern Warfare 2 which was so bad that it turned off my enjoyement of all call of duty games for good. I now play rpg's which i never used to. 

It'd be Wolfenstein 3D, followed by Duke Nukem 3D and GoldenEye 007.

The genre used to be awesome didn't it?

I used to play a lot of Doom when I was little. But then I started playing RPG's and completely forgot about FPS and eventuallt I started to dislike them. Lots of years after I played Resistance and I loved it! I had lots of fun, and it was the first game I played online... Then I played Resistance 2 and I hated it...

7th gen combined with online KZ2

6th gen Black beat out Area 51

5th gen 007 GoldenEye

1) Call of Duty: Modern Warfare 2
2) Resistance 2
3) Call of Duty: Black Ops

A LOT

The Halo Series for sure. I wouldn't be able to tell you which one I have played the most, but it is either Halo: CE, Halo 2, or Halo 3. I know I have put 230 Hours into Halo Reach and I have played a little over 1,000 games of matchmaking for Reach. I have played a little over 2,000 for Halo 3 so I would probably guess 500 hours for Halo 3. I have no idea how many hours I have put into either Halo CE or Halo 2.

Counter-strike (non-source), Team Fortress 2 or UT (the first one, although I played UT2k4 a lot too).