You're asking a question where answers can vary greatly depending on the individual users location. Start by looking at coverage maps for your area to find providers with good coverage in all your normally traveled areas. Then start doing searches online for local users of each provider to see what their experience in your area has been. I use and love Verizon as their internet speeds are great and I always have excellent call quality. (in my area) I may travel somewhere else in the US and find that service there may be horrible. For a low cost carrier with no contracts and pretty good service take a look at Boost mobile. Their internet is not stellar but voice and text are good and you get unlimited everything for under 50 per month.