Back in the day when I was an incredibly homesick 20 y/o trying to make my way in NYC, I'd take weekend flights back home to my friends and family at least twice a month. Always on Delta, and usually the same itinerary. Of course, the crew changed constantly but there would be some FAs that showed up regularly.

I remember one flight attendant who would introduce herself as "Penny, just like the coin." After having this FA two or three times, I recognized her so when I walked on the plane the next time and she greeted me I said, "Hi...Penny, just like the coin, right?" I could tell she was really tickled that someone actually paid attention and remembered that. She asked what my name was and then later on asked me by name if what I wanted to drink. Crazily enough, the next time she happened to be the FA, about a month later, I again said, "Penny, right? Just like the coin?" to which she replied, "Oh hey, welcome back!" She didn't remember my name, but she definitely remembered me.

Now I fly on multiple airlines to different destinations so that'll never happen again, but it was pretty cool when I started recognizing the usual crews. These flights were always Delta Connection; I'd imagine this kind of thing is only common on regional carriers.

Nevertheless, I'm sure other people here have similar experiences; would be interested in reading them.