It can be on any console. I'm just wondering what some of your answers are. It can be for multiplayer qualities or just single player.

Prototype 2!

Mass Effect

My parents couldn't buy me nintendo 64 as a kid. I used to go to target and play mario kart. good memories.

PS2-Metal Gear Solid 2: Sons of Liberty
PS3- Metal Gear Solid 4: Guns of the Patriots, Resistance 1 & 2
PC-Descent II, Megarace, Oddworld: Abes Oddysee, Team Fortress 2, Halo 1 & 2, Half Life 2, and WoW
Xbox and Xbox 360-Every single Halo game

I don't have an all-time favorite as it'd be too hard a choice

The Legend of Zelda Ocarina of Time.

Okami and Shadow of the Colossus.

SOUL REAVER

My all time fav game would be WARCRAFT III !!
No doubt about it...if you test that game on the scale of time...its a legend after revival touch of icefrogs DOTA !!

Mine are still the original Tomb Raider and Panzer Dragoon.
I was around 20-21. My first construction job. $12/hr was pretty darn good for a 20 year old kid in 94/95. First place away from home with three or four revolving roommates. Plus all our dumb buddies around all the time. Staying up all hours getting completely faced on anything we could get a hold of and playing Sega Saturn.
Good Times.