I wouldn't complain if I had a chance to see any of the following actors in a porn production:
Robert Downey, Jr.
Jonathan Rhys Meyers
Seann William Scott
As for actresses, it would be interesting to see someone as classy, poised, and elegant as Gwyneth Paltrow, someone as exotic as Salma Hayek, someone as sultry as Scarlett Johansson, or someone as wholesome as Amy Adams or Zooey Deschanel.