The only real description we get of Crowley is that he "...had dark hair and good cheekbones and he was wearing snakeskin shoes, or at least presumably he was wearing shoes, and he could do really weird things with his tongue." Ladies and gentlemen of the jury, this troper rests.
This troper can't blame her incubus fetish on Crowley, since she had it long before she read the book, but God knows he hasn't helped any. Mmmm, sunglasses. She's also heard at least one person toast Crowley/Aziraphale as introducing them to the wide world of slash.
All girls may indeed want bad boys, but this troper would much rather corrupt a good boy, and therefore has an incurable Aziraphale thing. It helps that this troper...likes books. A lot.
This troper will confess that Good Omens Slash Fic planted the seeds for her sin and punishment/retribution fetishes, as well as A Thing for the fall/falling from grace. U-unf.
Does being attracted to the female personification of War count? There's also the somewhat thriving War/Pepper community.
How has no one mentioned Famine/Pollution? It's got a healthy following, believe me.
Pollution himself is just really, really... wow. Pale, languid, gazing around in a romantic way, young-seeming, bishie... yes. (come to think of it, the paleness/languidness does a bit for my H/C kink, too...)
the way Pollution seems to be permanently half out of a daze just makes this troper completely hot. Ahh....