According to a recent survey of over 1,000 bartenders (a profession that observes more pick-up lines used than any other), the vast majority of lines don't work. Moreover, many provoke a visceral reaction. I would take it a step further and say pick-up lines convey a very inauthentic character.
All that said, pick-up lines have been used since the begging of time and I'm sure they'll continue to be used until the end of time.
The following are all actual pick-up lines used on my clients over the years. I've taken the liberty of giving each an approach type, so that you can fully appreciate the line. Out of the following, I do highly endorse one in particular. (View the gallery to see the one I most recommend.)