I play nethack it's like the game before diablo, looks badbut when you get further inlots of fun

The Epic Series is nice.
EpicPetWars etc.

And iMobsters as well.

This is a website i look at everyday it puts paid apps that want free for a day

http://freeappalert.com/

My favorites
1.tap studio
2.riddim ribbon
3.moron test
4. tap tap revenge
5.symmetrix