This is an incredibly complicated issue that doesn't have a short answer. There isn't a short answer to the above question because there are so many variable involved (what may work wonderfully for me with one carrier, one phone, and one location may work terribly for your in your location of the same carrier and the same phone).

Personally, I like AT&T and I like my Samsung, but they may or may not work for you. This thread is just going to end up like all the others with no real answer and a lot of highly divergent opinions.