The best line I've ever successfully used was complete silence. I walked up to a girl in a club, handed her my phone with the new contact screen on, got her number and then left with her about 20 minutes later. I wasn't sure if it was going to work, but it was more of an experiment than anything else and I bet a mate that I could pull it off.

This dude is too shy to approach someone, let alone use any pickup line.