My top 10 - obviously biased against wii, since i don't own it
Not really in order:
1. Gran Turismo
2. Grand Theft Auto
3. Call of Duty
4. Halo
5. Killzone
6. Resistance
7. SOCOM
8. Splinter Cell
9. Metal Gear Solid
10. Gears of War
If it wasn't nintendo bias, i'd probably have Smash Bros., and/or Mario in there.