I have Verizon (6 years now) and AT&T for business (8 years now). I prefer the Verizon for coverage & billing but I have the right plan and yes that matters 100%. Family plan (2,400 minute plan/unlimited text, etc.) with 6 phones and under $250 a month.

I prefer AT&T simply because of the I-Phone and other phone models but haven't tried out the Droids yet so that may change to Verizon soon.