Goldeneye back in the day
WWF No Mercy. I literally updated the game myself with rosters. I was in and out the library downloading CAP's like a feen. I did the same for the first 2 smack down games as well. I loved this series so much, especially when I was deep into wrestling.
Then NFL 2k5. I played it till 06 (the game came out in 04), manually updating rosters (creating players, trades, etc.) by myself with info from operation sports. It had to stay current with real life football, even though the series was over. I'm the same way with NBA 2k games, but NFL 2k5 was special...I was in a zone. I still own the game, I refuse to give it away or throw it out. Its very special.
But Halo 3 completely took over my life at one point. I lived Halo 3. I'm glad I was on and off on xbl during Halo 2 because it would have ruined my life. H3 ruined every other game for me, especially Gears 1. I played the fukk out of Gears for about 6 months till Halo 3 dropped and I couldn't put another game in my xbox. It was that serious.
I love competitive gaming (MLG) and the shyt I was doing with Halo 3...sheesh. I loved every minute of it. I'm hoping Halo 4 brings that feeling back. Halo is the goat console FPS series.