Pros and cons to both but I like hitch racks. I have several but my most recent one is a Saris Thelma II. This holds the bike by the tires and wheels with no frame contact. There are lots of hitch manufacturers besides Yakima and Thule. For example, check these:
http://www.etrailer.com/landing.aspx...FYVx5QodlEp6qA
http://www.performancebike.com/bikes...0#ReviewHeader