I agree with all of the titles that Grant listed. I'd also add:
Macross 2036 (you'd be surprised how many Robotech fans would've been dying
to get this)
Blood Gear (mechs, light sabers, various guns and tools of destruction,
large bosses, great cinemas - Americans would eat it up ^_^)
Legend of Xanadu I & II/Popful Mail (marketing would be the key here. With
Ys, Xanadu, Popful, Dungeon Explorer II, Neutopia, etc... could any system
even come close to the Turbo's action-RPGs?)
Fray~Xak Gaiden (a bit of a reach here, but Fray was the kind of cute,
adorable, memorable character that people could identify the system with)
Sylphia (another great shooter to add to the Turbo's already strong lineup)