Go At&T, I just left T-mo and signed over to At&t. It was the best move I made. I like T-mo but the options to have all the 3g goods is there. Trust me, make the move, you wont regret it.

TMobile is great in most areas. Check coverage. Where TMobile fails is with choice of devices and high speed data. For regular phone service, Tmobile has good prices and great customer service. Just don't expect data service better than GPRS or EDGE (for now).