Goodness, there are too many, so I will summarise the thread so far:
FF7 versus LOZ OOT
FF7 really drew you in and actually had you caring about the characters. It affected everyone who played it in some way or another. The music was superb and all the side quests and long storyline made it a very satisfying game. BUT, FF6 did EVERYTHING better. Maybe FF6 vs LOZ OOT would be a tougher call, but Zelda wins this one. Sorry FF7 fans, I like it too, but the fact that you can find tons and tons of FF7 Hentai and Manga everywhere must mean that the characters, rather than the game itself, are the more memorable features of the game. You know it; You probably still fap to Tifa Lockheart pics. Everything about Ocarnia was excellent, and set the standard for adventure games. I can't wait for Twilight Princess, It may be the best game ever as well. Who Knows?
I haven't played Halo or Half-Life, so I can't comment.
If this were a "greatest console" thread, then the answer begins and ends with SNES. There are too many excellent games to count on SNES. Really.
Best puzzle game ever? Tetris Attack (SNES). Before it became Pokemon Puzzle League <shudders>on the 64.
The best game ever cannot be determined, so pick from this list of my favorite ten.
No Particular Order
1. LOZ Ocarnia of Time (64)
2. Chrono Trigger (SNES)
3. River City Ransom (NES)
4. Final Fantasy 3 (6) (SNES)
5. LOZ A Link to the Past (SNES)
6. Nuclear Strike (Playstation)
7. Super Mario Brothers 3 (NES)
8. Final Fantasy 7 (Playstation)
9. Resident Evil 4 (GCN)
10. Super Smash Brothers: Melee (GCN)
I could list 30 games, but maybe another time. 8)