I've had a fair few.
Christina Ricci
Liv Tyler
Chloë Sevigny
Michelle Rodriguez
Monica Bellucci
Sofia Vegara
Kat Dennings
Neve Campbell
Shannon Elizabeth
Elle Fanning
Rose McGowan (before she cut her hair off, but I respect her activism and choice to leave Hellywood behind)
Ryan Gosling
Channing Tatum
Michael Pitt (when he was younger)
Edward Furlong (when he was younger and before the substance abuse took their toll)
Freddie Prinz jr (My first male crush)
Seann William Scott
Joel McHale
I also had a thing for Ethan Embry and Matthew Lilliard for a while because of them being in so many teen movies.
Singers/People in bands:
Davey Havok (singer of AFI) (my husband)
Tom DeLonge (of Blink-182 and Angels and Airwaves) (my other husband)
Brody Dalle (of the Distillers)
Amy Lee (of Evanescence)
Lady Gaga
Beau Boken (singer in Blessthefall)
I actually prefer to have fantasy crushes on people like that because you can't get hurt from them (well, unless they do something that makes you hate them, I guess, lol).