Super Mario Bros. 3 (NES)
Atmosphere, Gameplay, Challenge, it's all there, just an amazing adventure.

Zelda Wind Waker, it has everything I want in a game. FFVI runs it close, but WW takes the top spot.

Roller Coaster Tycoon.

Simply brilliant.

Probably Morrowind for me, just so much to do.

final fantasy by a mile cant pick which one

It's really a toss-up between Zelda: A Link to the Past and the original Zelda on the NES.

I guess if I had to pick only one, I'd go with the original for its standard-setting game design and the inclusion of the second quest.

Civilization I

Overall: Gran Turismo

This gen: Uncharted

My answer would change depending the day or my humor.
It could be Super Mario World 2: Yoshi's Island, Super Mario Bros, Final Fantasy VII, Fire Emblem: Radiant Dawn, Golden Eye 007 (N64), A link to the Past, Ocarina of time, Donkey Kong Country 2: Diddy's Kong Quest, Tales of Symphonia, Mass Effect saga, Red Dead Redemption or Dragon Age Origins.

God of War III - Nothing else comes close, it's my absolute favourite game ever, from my favourite franchise ever.
I love everything about its Art-style/ Boss Fights/ Characters/ Environments/ Epicness/ Gameplay/ Graphics/ Pacing/ set-pieces/ Sound/ Story... It's a totally stellar, thrilling and unforgettable gaming experience. In my opinion it's the best game made to date, Santa Monica Studios... bring on GOW4!