There's a few that I would consider the best, for very different reasons.
ISS Deluxe Snes - The first football game I got into and was amazing at the time and I still think would be a good laugh playing it now.
Actua Soccer PS1 - The first 3D football game that provided hours and hours of mulitplayer fun with beer. "Felipeeeeeeeeeeee!"
ISS Pro PS1 - As above but improved on the realism of actua soccer.
Doom PS1 - Multiplayer on this was immense. 2 TVs, 2 PS1s, 2 copies of the game. Used to play this with mates for hours/days on end.
From then, I moved into PC games and only really moved back to consoles with the Xbox 360 and thus the rest of my choices are from the 360, though they are on the PS3 too obviously.
Bioshock - Utterly epic game that I've played through 3 times and enjoyed each time. Visuals, sound, atmosphere and story all stunning.
Dead Space - Same as above really, another fantastic game I've played through 3 times and to think I didn't like it that much when I first played it.
Fallout 3 - Hard to choose between this and Oblivion but the post apocalyptic setting just wins. Amazing game with an enoumous amount of depth and so much to do which never ever got boring.
ISS Deluxe Snes - The first football game I got into and was amazing at the time and I still think would be a good laugh playing it now.
Actua Soccer PS1 - The first 3D football game that provided hours and hours of mulitplayer fun with beer. "Felipeeeeeeeeeeee!"
ISS Pro PS1 - As above but improved on the realism of actua soccer.
Doom PS1 - Multiplayer on this was immense. 2 TVs, 2 PS1s, 2 copies of the game. Used to play this with mates for hours/days on end.
From then, I moved into PC games and only really moved back to consoles with the Xbox 360 and thus the rest of my choices are from the 360, though they are on the PS3 too obviously.
Bioshock - Utterly epic game that I've played through 3 times and enjoyed each time. Visuals, sound, atmosphere and story all stunning.
Dead Space - Same as above really, another fantastic game I've played through 3 times and to think I didn't like it that much when I first played it.
Fallout 3 - Hard to choose between this and Oblivion but the post apocalyptic setting just wins. Amazing game with an enoumous amount of depth and so much to do which never ever got boring.