Replying to Help me choose a cell phone provider

Ok so, I will need to get a US cell phone in the fall and if you have any input whatsoever for cell phone companies, please share your experiences.

The things I'm looking for most is... how is the coverage? are calls dropped? how often do you have issues? are there hidden fees which aren't easy to find on the companies' website?

As well, I'm not familiar with cell phone technology, but I'm looking to buy a phone not offered as a contract phone anywhere in the US. If I buy such a phone, will I be able to use it with all companies? (LG Shine; is a GSM phone which works on 900, 1800, 1900 bands)

Thanks!