Band Member x Fan (Had a series of RP's on this subject. Have rodied for several bands; lived with a series of crazy musicians. I particularly enjoy playing the band member.) Got LOADS of material.
Vampire or Were-thing x Human (I am currently doing a 3 way with a male vampire and female were-cat. I am the "unsuspecting human." I find it VERY hot! We're just about to "get busy")
Angel or Demon x Human (Had a lively RP as a pagan norse warrior who buys an angel as a sex slave. Lots of religious conflict. If she doesn't give in to his depraved desires; he will sell her again; still a virgin. He does, however, spooge all over her in any way he can SHORT of penetrating her precious maidenhood. Humiliation, bondage, yadda, yadda. She ends up pregnant with his child by her request.)
Any of these ideas appeal to me; let me know if you'd like to see a plot fleshed out for you.