Here are several reasons why I prefer an Android phone over the more popular iPhone:
Google Services are much faster
I'm an avid user of Google services (Google Maps, GMail and Google+) and these services are a bit slow (particularly Google Maps) on the iOS environment on which I was disappointed. Having these services as native apps on the Android ecosystems makes it more faster and (in Google maps' case) more accurate.
Custom Launchers, Keyboards and Widgets
So there are the major reason why I choose an Android Phone over the more popular iPhone. This blog is nothing against Apple since I do like some of their products (the iPad and the iPod Touch) but when in comes to a mobile phone, an Android phone is my personal choice.