Similar to my thread about interesting coins in "coin chat", What is your favorite paper money given in circulation? Mine is the 1999 $5 Star (although it's worth about face, it's my first star).
I had a $50 bill dated back in the 50s or 60s (can't remember exactly) - this was some time in the mid-90s. $50 was too much for a kid to hold on to, so it found its way into my savings account. I also found a star $5 around that time, thought it was a bit weird, and spent it. I've come across many $2 bills, though. Sometimes people would pay for things with rolls of them.
Well, I don't have much, but I found a VF Series 1950 A $20 in my till at work once, so I bought it! I'm holding on to it to see if it will go up in value as the years fly by! (And so if I'm ever broke, I can at least have $20 saved up!) ~AJ
Ah you left out Web Press notes, I actually got one of those in circulation several years ago in the Upper Peninsula of Michigan.