I like the Android based smartphones (have a Droid X) because I prefer Google's openness vs. the closed, controlling attitude that Apple has in general. An excellent example of this is AppInventor for Android
which is an attempt by Google to give non-developers a way to create their own apps. It's still in Beta but has a lot of potential to open up Android app development.
Not to mention that I wanted to stay away from AT&T as my cell service.