We have had Virgin Mobile unlimited for 8 years without a single problem.
Virgin Mobile is great. I've had one for more than 8 years, haven't had a problem in 10 years, and it's a pay-as-you-go phone. I have expensive phones -- they have their uses -- but the lo-tech cell phone @20c/min never fails at what it does, and it's good as long as I add $20 every 90 days.
As for Verizon, I have problems with them regularly and have been looking forward to Monday to call them about the most recent one.