well if i'm gonna be honest, if i was single, there's probably not many i would turn down if given a wink and a smile. even they fatties (hey, big girls need love too!)
but if we're talking people that we'd give our left testicle for, just to be given the chance to dangle the right one in their mouths, my list would probably go something like...
Rachel Bilson (had a thing for her ever since i was a juvi watching OC)

Selena Gomez (hey, don't judge me...she's legal these days!

Britney Spears (i'd do unspeakable things to this girl...and i reckon she'd let me!)

Natalie Portman (It's natalie portman, why the hell do i need to justify myself)

Christina Aguilera (i've wanted her to rub the genie out my bottle ever since she released her first single)
i'll add more as i think of them