A Collection of Fabulous Come-Back Lines

Man 'Haven't we met before?'
Woman 'Yes, I'm the receptionist at the V.D. Clinic.'

Man 'So, wanna go back to my place?'
Woman 'Well, I don't know. Will two people fit under a rock?'

Man 'I'd really like to get into your pants.'
Woman 'No thanks. There's already one asshole in there.'

The most memorable rebuttal to a turn-down (used by the guy who used to live across the hall from me in residence) when he asked a girl to dance and she refused:
Man 'Want to Dance?'
Woman 'No, thank you.'
Man 'Don't thank me, thank God because somebody asked you.'

Man 'I'd like to call you. What's your number?'
Woman 'It's in the phone book.'
Man 'But I don't know your name.'
Woman 'That's in the phone book too.'

Man 'So what do you do for a living?'
Woman 'Female impersonator.'

Man 'You know, I'd really love to travel to exotic places with you.'
Woman (tries to ignore him)
Man 'You know what? I also love sex. What do you say to that?'
Woman 'Hmmm...you really love sex and travel?'
Man (nods his head smiling)
Woman 'Then go take a fuckin' hike!!!'