As far as Elf pairings go, I prefer Elf/Magic user
Vampire /G.Reaper sounds interesting
Vampire/Magic User
Superhero/Supervillain (or superhero/superhero where one turns into a villain)
Angel/Elf (maybe)
Magic User/Apprentice
Magic User/Warrior
Artist/Subject (I have a slight idea)

What do you think? I don't do no more than five with one person.

Also you didn't state (or maybe i didn't see it) what pairing types you prefer. I do mostly all.