I am tied between Lynda Carter's Wonder Woman, and Rebecca Romijn's Mystique.

The pro-advantage of Mystique is she could morph into any woman I wanted and therefore I would never be cheating on her. Downside: She'd probably kill me, just because she can. She's naked all the time, which is both hot and tiresome at the same time. Doesn't leave much to be imagined or desired.

Wonder Woman makes me wonder a lot of things, like what all she can do with that golden rope, and wondering what's under that outfit. Then there's the whole Mile High Club in an invisible jet thing. Yeah... I think I'll go with the good girl.
GUYS You can pick ANY female superhero you want! You don't have to stick with only the two that I chose.