My last phone's carrier was Virgin Mobile, and I was on a pay-as-you-go plan as opposed to a contract. This served me pretty decently aside from the outrageous price of $0.25 per text message sent and received, which really started to bite me at the end. Don't really have a preference aside from which ones offer me the most value. I hold no loyalty to Virgin unless they can let me keep my old number and nobody else can, and even then it's not that big of a deal.