Is it ever the phone company you like the most? For me it is the one I hate the least. They are all great when you are buying something. Service later is always a problem, because you are on the hook with a contract.
The ONLY reason I keep AT&T is the iPhone. For me, it is a must-have item. My contract expired last year, so I can move on now, but could not make it without the iPhone...I hope the new iPhone 4G will have services other than AT&T...