yeah definitely the gc app obviously. angry birds is a classic and pretty fun although i got bored with it pretty fast. any puzzle games are good time wasters, i have block puzzle 2 or unblock me. they're both good and have tons of puzzles.
Gameboid. It takes a while but it lets you play gameboy advanced games on your phone. Its awesome. Or get an e-reader app and culture yourself. Get angry birds obviously cause theyre free.