Should I buy a 13 inch MacBook Pro (2011) or a 21.5 inch iMac (2011)?

I would like portability...but it's not too important to me. What I really want is a lot of power. Although these are both baseline models, the iMac is still the winner in performance. They are the exact same price so I'll be spending the money either way. I love both computers. I am in to gaming but don't want to buy a pc. Please, personal experiences are very welcome. Any other help is good too! Thanks!