What couple that wasn't would you like to have seen together? They can be film-based or from a book.
My couple is from one of my favorite tv shows growing up. It had very little to do with the movie it was based from and all to do with being wacky, gross, and a little dark.
He was a petulant poltergeist from the Neitherworld who could shapeshift into anything imaginable. She was a spooky goth girl from our world who loved the strange and unusual.
Beetlejuice and Lydia!
What I love most about these two (besides the whole premise of the show) is the friendship which seems to be missing from a lot of YA romances. If I wrote a romance, I'd want it to be as fun, spooky, magical, and loyal as this friendship. And, of course, with that spark and chemistry that makes a romance a romance.
What about you?