One that I've actually used:
"Look... Me and my buddy over there are on a double blind date... To be frank, we're dying. I know when to quit while I'm ahead, but he doesn't. You've been stealing glances at our table all night.
"No, I'm not coming on to you. Women don't steal glances at me. No one looks at a fatass like me that way anyway. I'm more 'last-call desperation' and I know it. Even then it'll be just me going home in a dirty taxi alone and plastered.
"Well, I'm about to excuse myself and once I do that I fully expect the two women to leave as soon as my buddy steps away to the bar again. Knowing him, he'll stick around and have a drink. If he was really disappointed, a dessert too.
"Anyway, I'm wasting your time. Back to the point: He likes baseball and fishing. Tip: when he's enjoying himself he drinks beer otherwise he'll get a cocktail or shots. He has a big doberman that he gushes about. Get him to talk about the lake or the last game he attended. Good luck."
Worst pickup line because I, in fact, went home alone. My friend had would gain and off-and-on girlfriend, who would eventually become his future daughter's godparent.
Although I admit, I was correct. I would go home alone from every late bar visit during that decade of my life. The following would be the same and the current decade isn't looking too good.