People always used to tell me that I looked like Tarja Turunen from Nightwish, when I had long black hair, and when I then had it closely cropped, I was likened to Sigourney Weaver and Sinead O'Connor.
I've also been told on occasion that I looked like Toni Collette, although I could never really see the resemblance there...
Miss Kat Dennings. I obviously look like her so much in real life that half of my facebook friends thought that was me when I posted my doppleganger photo. Sad.
Almost everyone tells me I look like Ashley or Mary Kate Olsen. I sometimes get stopped by random strangers just to tell me that. I really don't see it at all though. I don't think I have an accurate doppleganger. My friend Megan thinks I look exactly like Cameron Diaz, but I don't understand that comparison either.