I wish one of those companies would just stand up above the rest and not suck. They are all so shitty. All the new phones in america suck. I'm still using a super old nokia and I was going to upgrade it, but all the phones at the store were all pathetic. At least congress made it easy to switch to a new carrier because of the number-portability bill.
I'm with verizon right now, who generally have a great network, but I would drop them in a heartbeat if something better came around. However i hear nothing but bad things about AT&T (nee Cingular) and sprint usually doesn't have the best coverage, although I have thought of switching to them because they have some great plans. T-Mobile isn't any better either.