Mine would have to be Final Fantasy VIII without a doubt!

 What? VIII was the worst.

Best online game of all time : Quake 3 arena on the PC my name was s1lent_assasS1N or enVy in the later years if you played the game :) Too many games to make a decision but I'd say Gears of War 1 stands out because it was the first "Next Gen" game and so much fun.

I can't pick one because it's hard to do with all these different genres so i will put 5

1. Ocarina of Time
2. Final Fantasy VII
3. Doom
4. Super Mario Bros.
5. Rock Band/Guitar Hero

Final Fantasy VII was amazing.
Played it through at least 5 or 6 times. Still have it in the PS.
This is one question that can never be answered.
Lets all agree each system has at least one amazing game.

I never played Final Fantasy VII but for now I think Legend of Zelda ocarina of time is the very best game of all time.