Best Cell Phone Carrier?

[Dravyk]

This thread confirms what I thought, that X service is great if you live in Y locale, and A service is great if you are in B locale, etc. Cingular seems to be popular in the West Coast. Nextel (and Verizon) in the Northeast.

(For example, I get clear signals on Nextel at my supermarket. When I had VoiceStream that became TMobile last year, I was about the only person in my supermarket who could never ever get a signal, which totally sucked.)

The thing is, most of us here travel a lot. What service is "the best for everywhere"? Does such an animal even exist?