The battle between Android and iPhone is a battle which has lasted many years and will continue for many years to come. Fanboys from each side battle it out in the comment sections of most technology sites which cover either topic, it's quite entertaining actually. Their are advantages on both sides and most if it comes down to preference. I don't think there is one which is better but no one can deny is the one winning when it comes to the amount of activations. But then iOS is only limited to 3 different types of devices.
Note: This infographic is from 2011, after the first quarter so statistics are not up to date. As many will know, the technology, especially mobile market, evolves very quickly.