Primal is essentially Paleo plus high-fat dairy.
Like Paleo, but a little easier for those of us who like to eat some cheese and cream. Mark Sisson is a well-respected member of the ancestral health community, and his books dominate the Primal arena.
Another classic. Lots of insights, easy to understand, and fun to read. Mark makes compelling arguments but keeps it simple.
Link to his blog here: Mark's Daily Apple