I'll usually say "Hi! How are you?" And / or give her an honest compliment on jewelry or clothing.

Intentionally bad pick up lines are the best! Somewhere, I have 1001 TESTED pick up lines and answers (I think we only got to 5 or 6 hundred) years ago...from raunchy to the absurd....I remember the last one, though:
Hi, my name is Johnny, and would you like to buy insurance for you life and family in this time of trials and tribulations? (You are hoping for a 'No' answer...I believe I got a 'Whaaaa?' or 'Huh?' No, well, good, cuz I am not selling any, but I would like to know your name and buy you a drink.

None so far on this site-The one that worked on me resulting in a very unhealthy 10 year on/off relationship was "I work hard and play hard."

I remember a time when I was a kid and my friends all had a bet. Who could do the worst pick up line.

We were swimming around the harbor near the beach recreation area. I saw a girl around my age floating around in an inflatable hoop/ring. I was about 20-30m away and I was a pretty frequent swimmer. So I took 3 quick inhale/exhales then took in a deep breath, swam down 3-5m and across in her direction. I'm about 6m below her now and I let out 90% of my air. I watch the bubbles go to the surface and then I resurface 3 meters away from her and I'm like "Hey there, you're so beautiful that you've left me breathless"

Prettiest lady (in my mind) in this great big Honky Tonk, turns to me and says; "Do you come here often?" She has been my Lady for 27 years now.

bumps/backs into me while wrapping up a story with, "...spherical chickens, of uniform density, in a vacuum. Oh, excuse me miss."

If I said you had a beautiful body, would you hold it against me?

None work on me. It's a turn-off to me.