If you are looking to use the full potential of what your phone is capable of...
PlayStation emulators are pretty sweet, especially if you have a ps3 controller you can hook up to your phone.
Shadowgun is like gears of war for your phone with amazing graphics and gameplay (one of the best to date)
Backstab HD, Six Guns are some wicked awesome rpg/action/adventure games with crazy good graphics and huge in game worlds.
Order and Chaos is probably the highest polished mmorpg with best population. Great gameplay as well.
GTA III .... do I have to say anything else? Its the real live full game!!
Freeplay is the new free Sims game pretty cool if your into that...
I like Osmos alot as well... nothing crazy just simple and looks really cool haha
/my2¢
Pin it to Win it.