I am NOT going to start listing every single age-old game I still play on a regular basis, so I'll just include the games released between the beginning of this gen and the end of 2010.
- Street Fighter IV
- Minecraft Beta
- Donkey Kong Country Returns
Not that impressive, but I've said numerous times, that I spend more time replaying the older games, than playing new ones.
Though I'm pretty sure I'll still be playing Marvel vs. Capcom 3 a few years from now.
EDIT: Special mention to Super Metroid. There hasn't been a year, during which I didn't complete Super Metroid at least twice.