pickup lines hardly ever work.

dont use a pickup line, you gotta say a PIMP line. something smooth that is not cheezy like a pickup line and will send her over the top. for example...

"i think this was my best descision all night"

see, it sounds kool, but isnt cheezy. and trust me, it works alot of the time

No pick-up lines they get annoying and predictable.

Lol, grind a girl.

Good luck bro.

Learn how to dance or something, do a crowd pleaser, get all the girls you don't want

^^This

It's possible to make a pickup line that doesn't sound like a pickup line, and those are the only ones that are going to work. The ones that work in other situations aren't going to get you a girl unless she already really likes you to begin with, and then the pickup line isn't even necessary. Stay away from such things as "I seem to have lost my phone number, can I have yours?" Those ones just make you look kind of creepy.

i agree. this is a good line.
guys who use too many slimy pickup lines are just plain creepy.

dude, imo, you dont want her to be your gf until youve at least talked to her a bit. she could be your worst nightmare for all you know until youve got to know her a bit. id say ask for her number after a dance, text/call her for a while, then ask her to hang...then, if you still think you like her, ask her out. IN PERSON. because nobody likes it when you ask someone out via text.

Lol, better yet "This was almost the best decision I made all night" would work A HELL of a lot better.

lol ok if you say so man....if i did that, i just KNOW i would get in deep shit with some girl whose personality i could NOT stand.

lol ok, as a girl, i have to say that pick up lines are sooo outdated and really cheesy, however that's just me. I'm sure there are some out there who are turned on by that.
Also the whole "girlfriend" part could be a real turn off for some girls.
Be careful though because there are some girls that don't take well to random guys grinding with them, and they will turn around and cuss u, or slap u or just leave.

I would advise you against that completley. The first reason would be that pick-up lines are cheesy and rarely work. The second would be that approaching a girl and grinding her isn't the best idea, personally i'd get the impression that you're only after one thing (most of my friends feel the same) and if the girl doesn't like you in that way or is slightly shy then it puts her in a very uncomfortable situation. Neither of which is going to help you get a girlfriend.
If you want to approach a girl, then just start with a simple hi and a smile, seriously that one rarely backfires, start dancing with her but stand at a distance, don't try and grind her straight away, after a few songs then start dancing gradually closer to her but watch her body language, if she pulls away or starts to look arkward then stop!
Good luck.