i would say at&t because they give you more for your money than verizon wireless. They give you rollover minutes, good network, and a good selection of phones. I have been an at&t customer since 2007 and I have had NO problems what so ever. I think since 2007 I have only dropped a call twice. Once when it was raining really badly and another time when I was in the car turning near a huge mountain.
So I would say that If i pay the same as every verizon customer but I get to keep EVERY minute that I paid for and not get them thrown away, then I think that right there shows that at&t wants their customers to actually get the most out of what they pay.