I like to just walk up behind girls and whisper "...prepare for unforeseen consequences..."
- Hey Princess Peach, I'd fix your pipes anyday.
- Hey girl, you wanna hang out with the Koopa King.
- Everytime I see you I get a One-Up.
- In space, no one can hear you scream sweet nothings.
- You ready to meet your Final Fantasy.
I'd never use any of these or any pick up line in general.
Edit: I just realized this is yet another bumped thread. Well, at least it was an entertaining one.
Oh wait, I thought of another one. (Hey girl, tired of singleplayer? How bout we play some co-op together.)