Star ocean 3 with all the trophies to unluck
Guilty Gear series, most fighters have lotsa replay value
SSBB, same reason
Shin megami tensei : Nocturne... if you decide to make a new game for all the endings
Residen Evil 4 for all there is to unlock
Same for Devil may cry 3

Anyway, I'm the kind of guy who focus on a small number of games and replays them like a madman doing challenges and whatnot (like handgun only for resident evil 4 or Single class challenge for FF5)