Very consolecentric thread this one.
However mine would have to be Civ 4, nothing else gets close.

Honourable mentions are:
Medeval 2: Total War, Europa Universalis 2, Hearts of Iron 2: Doomsday (yeah im a Paradox fan, not for everyone I know) and Dues Ex.

Funny really as I play consoles about 10 times more than PC's.

Zak and Wiki could well end up here though

<edit> sorry FF7 has to be up there as well. For the Materia more than the stary though

 Why would VC (which uses emulators anyway) have more nostalgic value than any other emulator?

 As for my favourite game, I really don't know. I've probably finished 400-500 games in my time and I can't think of a single one which stands out far above the rest.

Probably Diablo 2 for Mac, i clocked a ridiculous amount of hours on that game, but for multiplayer action its gotta be Melee. But then theres UT04 which i go seriously addicted to a few months back.

melee !

This is absolutely, unquestionably the correct answer. Anyone who answers otherwise is wrong, and will be shot.

I prefer Chess to Go, but they're both at the top and I wouldn't be picky either way.  

super mario RPG. it's because I'm probably one of the only English people to have owned this game and it made me really appreciate how great the game was

The Legend of Zelda: Ocarina of Time is the greatest game ever made. No experience can ever compare to playing it for the first time. With a large, beautiful world, great levels, and excellent controls, this game defines greatness. No other game I have played even comes close to this one. This game is perfection. This game alone is a good enough reason to own a Nintendo 64.

I think that pretty much summed it up...

Super Mario Galaxy is the second greatest game ever made. No experience can ever compare to playing it for the first time (except for OoT). With heaps of small, beautiful worlds, great levels, and excellent controls, this game defines greatness. Only one other game I have played comes close to this one (the other one is actually better). This game is perfection. This game alone is a good enough reason to own a Wii.

My elections would be:

Zelda: Ocarina of Time: no need to explain...

Super Metroid: Best 2D game ever by far, the swan song of the 16 bit era

Final Fantasy VII: Tough VI is far a better game, it marked the beginning of a new era.

If I had to rank them, the order will probably be:
1 Ocarina
2 Super Metroid
3 FF VII

The reason for this is that, while the 3 are total masterpieces, FFVII had not aged as good as Zelda or Metroid, it looks totally dated nowadays, while Zelda is still a blast to play (Im talking about gameplay here)