How to use PS3 controller for android, nexus 7 Tutorial
There are two methods for doing this, one is connecting the PS3 controller via a On the go (OTG) cable to Nexus 7′s micro USB port
this method only works with certain games that support external controllers, simply plugin and play.
The second method is more difficult and requires you to root your nexus7 first – The tutorial I posted here should help you do that, the second method allows you to play any game with your PS3 controls wireless through bluetooth.
The second method you will need the Sixaxis app from google play, this app allows for mapping PS3 controllers – setting profiles to make games work the way you want with your gamepad.
Sixaxis controller setup guide
The Playstation 3 controller is recommended but people are using Xbox 360 controllers too.
You can pick an Official Sony DualShock 3 Controller (PS3) from my affiliates site amazon. There are cheaper controllers that work but if your serious about playing games then go for quality.