You didn't mention if you're looking for free or paid games, so little bit from both (and i'm also guessing that you don't have high-end device) :
Free: Cut the rope (all versions), angry birds(little bit above 40M), Ball Pool, Fun run, can you escape/100 floors, iStunt2, UnblockMe
Paid: Wher's My Water? (+40M), Terraria, Sonic The Hedgehog, Super Hexagon, Sprinkle, Flight Control, Amazing Alex