I have both the iPad 3 and Nexus 7 (16GB), and I use my Nexus 7 more. The smaller size makes the Nexus so much more portable, and the lower price keeps me from worrying about losing or damaging it.
I have an iPad 2 (32GB) and a Nexus 7 (16GB) and i definitely enjoy gaming more on my Nexus 7... not so much for watching movies however with the smaller screen, for that I still prefer the iPad...