A couple, but not many:
- D&D (BECMI, 2e, 3.xe, 4e)
- Cyberpunk
- Mekton
- Fuzion
- Palladium's Robotech
- L5R
- Star Wars d6
- Tri-Stat
- Twilight 2000
Other than D&D, Cyberpunk, Mekton, and Fuzion, the rest I found so bad as to be virtually unplayable.
Needless to say, I stick with D&D 3.5...