Human on Witch
Notable Examples: The Witches of Eastwick (1987), Bewitched (1998), Practical Magic (1998), Harry Potter and the Half-Blood Prince (2009)
Because witches tend to be played by smoking hot movie stars (with Hocus Pocus and The Wizard of Oz serving as outliers), human/witch hookups aren't uncommon.
Nowadays, human-on-witch romance isn't just an adult romance novel fantasy; it's being popularized by young adult movie franchises, namely Harry Potter and the upcoming Beautiful Creatures, which is set to be the next Twilight.
Forget the days of green warty witches and the tragedy of the Salem witch trials, it's time to talk about wizards and witches as this generation's Prince and Princess Charming.