Any Good Costume Ideas?

Hm. For impressive in a courtly way, Cinderella's a good call, especially if you're gunning for the Disney set. Elizabeth Swann from in Pirates of the Caribbean would be impressive, but also difficult (and likely costly); you could also go for any of the Renaissance ladies (From the princesses in Shrek to the Guenevere variants) or something like the ladies dresses from 'Becoming Jane".

For the really distinctive, (and classy), you can't go wrong with Hepburn, or Jackie O.

Find your nearest professional costume store (ask the Drama teacher at your school). A night's rental shouldn't run you much, and should get you a good deal of costume; just be sure to sign up to rent well in advance.

I agree with epavlora - do something, old Hollywood - elegance, grace, AND sex appeal

Just try to find out what he likes. I say Marylin Monroe. She is pretty cool. I'm sure he will like what ever you are.

If you wanna impress a guy without appearing slutty, dress feminine and romantic. Long, full skirts rather than short, tight skirts. Maybe something with a petticoat. How about Scarlett O'Hara in Gone with the Wind?

What about sleeping beauty? Her dress was long or little red riding hood, Minnie mouse and Daisy had some pretty conservative wardrobes as well. good luck

Go as Aerial from The little mermaid.

The Wizard of Oz Dorothy isn't too slutty. Or you could be Nancy Drew, just by using stuff around your house. She wears skirts, loafers, and a nice top. You could even flip your hair out to look like her and carry a magnifying glass. That is not slutty, and nancy drew is in movies. Or if you aren't into that you could be Pippi Longstocking. Wear bright tights like orange or two different color long socks, black shoes, a reddish shirt and an apron over it. And you could do your hair in two pigtails.

Well, you could be like the spartan woman in 300, my roommate worn a costume like that for halloween, and she looked pretty without looking skanky.