As far as provider it really depends on your location. Where I live Sprint is the best, I've actually been with Sprint/Nextel for nearly 12 years. Best prices hands down!
As for phones, Droids are the way to go J. I have the Samsung Intercept and love it. If I had the extra money I would have gotten the Epic. Reason I didn't is the 4G phones require you to pay extra for 4G service EVEN though it's not available in my area for more than a year from now