Running up Pikes Peak at high speed (closed course, professional driver; kids and goofballs don't try this whether at home or not). Killer fun*. Not so much fun, but almost: running downhill on Pikes Peak at high speed. Risk of seat damage (pucker factor)*.
My miserable EXwife would take our sons to a clothing store to "buy" suits or nice clothes for a wedding or special occasion, then after the event, she'd take the clothes back for a refund, saying they didn't fit. She also did that with winter coats, jackets, etc., during brief cold spells. Allow me to disclaim that activity: she never did it while we were married and never with my foreknowledge or consent. I discovered the practice from 'informants' while we were divorced. My boys told me she did that all the time with her own 'nice clothes.' Did I make it clear she was my EXwife? Just one of the many reasons . . .