Which carrier would you choose?

Okay, so my "Experiences with Sprint" topic got a lot more discussion then I though, and while I originally was excited to switch to them for unlimited data, I now am completely turned off by that idea.

So I wanted to ask:

If all contracts ended tonight and you were looking at the 4 major mobile carriers, who would you choose and why?

I know all the different plans pretty well after studying them up, but give me some overall experiences, things you like/don't like.