I haven't played a lot of these but I can only tell that World of Tanks Blitz
is surprisingly good, even on my Xperia smartphone with merely a dual core 1 GHz and 1GB of RAM. Since I was a fan of World of tanks on PC in the past, I did enjoy the Android version as well. The game was also released for iPhones and iPads, I think.
Another one that I have played recently is one of a new type of games - EZ RPG
. It's like you enter the game once a day or two just to check how your characters is doing, equip some new gear and sell stuff gathered from the previous checking and then you can log out. And even if you are logged out, the character still fights with enemies, gathers stuff and experience. Pretty addicting, I'd say
At the moment I only have Mind Games Pro
that are games that take let you excersise you brain in its different areas, and that's it