Its basically impossible to have a definitive 10 games at the top for mess I'm always switching new ones in and out. I'd say the top 3 are set in stone but everything after could stay or fall off the top 10 at any time. But for the moment, here goes...
1. Earthbound (SNES, 1995)
2. Super Mario 64 (N64, 1996)
3. Donkey Kong Country 2: Diddy's Kong Quest (SNES, 1995)
4. Super Mario World 2: Yoshi's Island (SNES, 1995)
5. Conker's Bad Fur Day (N64, 2001)
6. Super Mario RPG: Legend of the Seven Stars (SNES, 1996)
7. Donkey Kong Country 3: Dixie Kong's Double Trouble (SNES, 1996)
8. Dark Souls (PS3, 2011)
9. Bioshock 2 (PS3, 2010)
10. Final Fantasy IX (PS1, 2000)