Well, my go to backups would be: 7th Sea, Changeling, Dark Heresy, Feng Shui, Legend of the Five Rings, Shadowrun, Warhammer FRP... and that's just the stuff in my bookshelf.
Considering my group's resources, any of the old school WoD settings, Deadlands, Agoné, Macross/Robotech, Rifts, HERO...