Final Fantasy VI - While the gameplay was just bad, it had a wonderful story, incredible characters, and fantastic music. When you ask people about some of the most memorable moments in a game, FFVI almost always pops up and when you ask people about music in a game, The Opera House of Dancing Mad always comes up.

 Also, who can deny that Kefka is one of the best villains ever?  Who else has ever gone from lackey to actually succeeding in taking over the world in the time span of the game?

Woot double post!

Outpost 2 or maybe LOZ ocarina of time

Woot triple post!

Diablo 2: LoD
Warcraft 3 : TFT
LoZ:OOT

Yes.

i would have chosen banjo-tooie if rare would finally release a good game again

Easy... Counter-Strike. No game has swallowed my soul like that one did. I played it for three years and probably logged tens of thousands of hours on it.

Paper Mario (N64)
Halo 2 is a close second

Any Zelda game for me.

Although, Knights of the Old Republic got me going.

OMG! There is another Earthbound lover out there!  For me it's between Earthbound, Chrono Trigger, and Starcraft.  All 3 of those are amazing and I have trouble picking between them.

SUPER METROID!!!!