it depends on how a guy says a pickup line. If he says it jokingly with a cute smile, he might get a laugh and a sarcastic response from me, depends on the person. If the guy is serious and just plain sleazy/ the pickup line is perverted don't expect a response.
I actually had a guy say this to me when I first moved to Boston, 'If you'll sit on my face, I'll eat my way to your heart' I burst out laughing and he walked away, but it was original.