I can tell you that Verizon is not the cheapest, at least not in my area, but they are most definitly the best!  I've been on nearly all of them, and Verizon beats them all hands down.  Againn, that is in my area, at least.

Verizon will terminate your service is you use over 5GB a month - and Sprint doesn't limit usage at all. So if you're planning on slinging a lot, you need to go with Sprint. I've never heard of anyone getting terminated from Alltel, either (and I'm in Kansas, too!) - sheureka