What's the best pay-as-you go cell phone plan on the market right now?

In customer surveys, Virgin Mobile receives the highest overall scores for prepaid wireless customer service, pricing, plans and account management. Subscribers give Virgin Mobile high ratings for call quality, even though its calls use the oft-criticized Sprint Nextel network. Some professional reviewers say Virgin Mobile's prepaid calling plans are confusing, and its website can be hard to navigate.
Customers also give Virgin Mobile low scores for the quality of its phones. Monthly plans start at $20 per month with no contract, and you get some free nights and weekend minutes. You can also choose to pay per minute. Overall, reviewers say Virgin Mobile is best if you plan to talk more than 300 minutes per month, since the $25-and-up plans give you some free weekend airtime. If you only want occasional use, then reviewers recommend T-Mobile To Go (starting at $10 for 30 minutes).