If you don't have it already, [app]Zenonia[/app] is good. I've also been enjoying [app]Soosiz[/app] a lot lately.
well depends on the genre. I agree with zenonia and soosiz. Maybe Undercroft or Bobby Carrot or Hook Champ or Crystal Cave Defenders or a match 3. Nick Chase (just saw there was a price drop on that one too)? I mean there are a ton of games to keep you occupied for a good amount of time! Just depends what kinds of games you like!
gangstar west coast hustle-50 missions alive 4 ever-30 levels+survival and unlockable weapons boxhead-very replayable
Guiness World Records. No joke. I played this for 3 hours straight going to the beach. It has 36 minigames each with a preset regional, national, and global time. You can customize your character. The preset world records are actually pretty hard to achieve as well and will keep you entertained. Online leaderboards as well. And if its not your thing. Get boxhead.
Dotopop is pretty fun, Samurai: WOTW, UnblockMe [all are $1] and HookChamp [$3] is pretty goddamn fun lol
I just picked up Robocalypse, and have already put several hours into it (and can see myself putting in many more). So if you like RTS games, that would be a good choice.