I'm not sure I should say any here, I may have used one or two (or 164) on girls on this forum.

Anywho, I usually make them up on the spot. Every woman is different, and with each one there is a specific pickup line. You just have to be able to figure out which one to use.

What comes to mind right now is:
"I'd buy us drinks, but you're already beautiful, and alcohol would only make me less eloquent."
"I was already afraid you'd be this pretty, and I'd be too insecure to talk to you, but luckily for us both, alcohol seems to remedy this."

Funny one: Move up to a girl, look her deep in her eyes with a fond expression, slowly move your mouth to her ear, then ask in a deep and soft voice: "Do you have the time?".