Had At&T in NY it suxed I switched over to Verizon. That was about ten years ago. I have since moved to Fla.
Verizon service was great in NY and is great south of the Mason/Dixon. i was going to switch to Sprint but have no reason to.
Possibly sucked before the cingular buy out? I had cingular and now I have att. The phone works everywhere. Even on the north shore in places verizon doesn't. Big problem is that it has been getting steadily more expensive since att bought them.
I tried tmobile when I was in texas because I was thinking about switching. It worked nowhere. As another poster stated, it dropped calls ALL the time. That's why I got rid of Sprint in the first place.
T-Mobile offers a fairly new service where you can purchase one of their wifi phones and the t-mobile hot spot service. They give you a router for your house. When the phone detects a wifi signal/tmobile hot spot, your calls are free. Some FAs and pilots have been using them in Europe and making calls to the states for nothing. I was thinking about switching over but when you aren't in a hot spot the service is horrible.
A sprint and T-Mobile merger could be a very good thing. I have been seriously considering the new I-Phone when it launches though.