OMG, this one is easy.
Super Mario RPG: Legend of the Seven Stars, EASILY!
If you have not played it yet, meanwhile are voting for something other than it, do yourself a service and play it first before giving your vote. Good chance your vote will be swayed.
iPhone = Great gaming device. Don't agree? Who cares, because you're wrong.
Currently playing:
Final Fantasy VI (iOS), Final Fantasy: Record Keeper (iOS) & Dragon Quest V (iOS)