I use an Android Optimus V with the Virgin Mobile $35/mo. Unlimited Data and Texting + 500 anytime minutes plan.
I like Androids-- love mine, in fact-- but I'd recommend going with an iPhone because they're uncomplicated and don't require as much app-finding to get how you want them. Functional, if not fully customizable. I think Virgin does a pretty cheap iPhone-supporting plan as well, comparable to the one I use if not identical.