Cell Phone Plans?

I've found that unlike other cities, San Francisco has been somewhat challenging for cell phone reception in general. In the vein of backward logic, Verizon barely works in my house but AT&T works just fine. Does anyone on here have thoughts about what works best? What provider do you use? I still find Verizon to be good for most places, but it is quite frustrating having to use a land line to make calls in my own house.