[Addy]

My friends and I recently had a discussion about this and I can't pick just .. one. I have a small list of games that I like for different reasons, though:

Mega Man 2 or Mega Man X, 2 is more nostalgic, X is easier to just beat in one sitting.
Metal Gear Solid 2 is unbelievable, they just don't make games like that anymore. It's hard to explain without playing the whole thing. Post modern ass post modern gaming.
Phantasy Star IV. My first RPG, and it's amazing~
Spiral Knights, a more current game.
Borderlands. That was my life when I played it. Hype for the second.