I have Cingular, and it's great. I find the customer service to be very responsive (in NC, at least), and the coverage is great as long as you don't go to VA However, I've heard that the best provider is Verzion Wireless, but the downside with that is that they are TDMA (CDMA?) and not GSM (meaning you'll get better coverage, but "meh" phones [however, Verizon's latest phone offerings look very good to me]). My cousin uses VZW and he really likes it; I've used his phone before and it does get great quality. As for the others: my Dad has AT&T and I don't like it much. Dropped calls and the like with my Dad (even though his phone is a TDMA phone). I haven't tried any other service provider. Hope I helped!
well, in the new york city tristate area, verizon's network seems to be the best, although the same can't be said for their customer service. i recently switched from sprint to verizon and both of them suck in how they handle customer calls (sprint's network in new jersey sucks just as bad as their service people).
yup, nyc tristate verizon has the most complete coverage. you shoud never be without signal when outdoors.
t-mobile is probably next, but only if you don't go to places where the coverage map shows no signal. there literally is no signal in areas like stokes state forest w/ t-mobile.