There have been so many, but I still like the original Primal Blueprint by Mark Sisson. It was on the same library display as GCBC, so the first Paleo book I read and maybe I'm sentimental.
Robb Wolf's The Paleo Solution, the original human dietalso good with more science; The Whole 30 another variation on the theme of eating ancestral foods. Neanderthin was one of the first, more books discussed in the Paleo sub-forum. http://forum.lowcarber.org/forumdisplay.php?f=107

Diabetes Unpacked has more international authors, the only marketing I remember was the Kindle deal.