Someone mentioned Cloei... For the record, she is a great girl and a friend of mine. Her site is fantastic, and really in a class by itself. They have amazingly loyal members, and convert a wide range of traffic, from what I can tell. You wouldn't do badly promoting NakkidNerds.
While you're at it, most of the other sites in our coalition also have partner programs... Check out the (sadly out of date) site
http://www.quality-erotica.com for the complete listing of members. Almost everyone has a referral program. These sites are all top-quality, very unique, and most importantly the webmasters/stars (usually the same person) can give a personal touch.