I can think of a few:
- Boot Hill (TSR)
- Western (an old Swedish RPG)
- Deadlands (Pinnacle)
- Savage Worlds: Deadlands Reloaded (Pinnacle)
- Aces & Eights (KenzerCo)
- Western Hero (Hero Press)
- All Flesh Must Be Eaten: Fistful of Zombies (Eden)
- Werewolf: The wild West (White Wolf)
- Serenity (space western)
- Gunslingers: Wild West Action!
- BRP Devil's Gulch (Chaosium)
- Devil's Crossroad
Does anyone have any experience with these games, or others in the genre?