What's Your Favorite Video Game?

My favorite game currently is either Halo or Deus Ex. It will probably change once i get half life 2.

All Time Favorites:
1) Mega Man x3 - Snes
2) Mega Man x1 - Snes
3) Mega Man x2 - Snes
4) Diablo 2: Lord Of Destruction - Pc
5) World Of Warcraft - Pc
6) Super Mario World - Snes
7) Perfect Dark - N64
8) TimeSplitters 2 - GCN
9) Goldeneye - N64
10) Doom - PC