I want to storm your love palace...

Jill at Feministe had a great thread a while back called Worst Pick-Up Line Ever. It's a gold mine I tellsya!

Guy: You girls smell really clean!
Girl: What kind of a line is that?
Guy: An honest line, man! You girls smell like you take a lot of baths.

And my personal favourite:

You must be a grain of sand between 62.5 and 125 μm because, according to the Wentworth scale of sediment size, you are fine