Wireless Data

You asked a heated question - basically because what you're dealing with here is a lot of reps from lots of companies and providers, all of which are going to tell you to jump with their team, just because that is the natural reaction. Well I won't have the same knee jerk reaction as some here, and I will attempt to maintain a unbiased opinion. It's going to depend greatly on your location. Who has the best service in your area? Whoever has the best coverage/service/packages for you is your best bet. Generally speaking the speeds are all about the same, the reliability just depends on the network. Around here Verizon is pretty much the only game in town, so everyone uses VZW - therefor around here, VZW is the best choice. If you're happy with your AT&T service, and you have good 3G coverage in your location through AT&T, go for AT&T.

For the record, I sell Verizon.