Spin
In the 1950's every private pilot had to do spin training. At the time we nationally had around 300 stall spin accidents per year. After they ended the training requirement spin accidents have been steady decreasing to around 20 per year. The danger is not from the accidental spin but from spin training itself.
Spins are not something to mess with. The majority of spin accidents occur during maneuvering flight and not when in the pattern. To me that suggests that thrill seeking pilots went up to do spins that got away from them. Practicing spins does not make you a safer pilot. Spin awareness however does. It is a good idea to be exposed to spins as a CFI however you should leave them alone unless you are in an aerobatic plane with chutes on.
Side note: I got my "no spin" AD in the mail last week and it was for the 150 and 152.
SKyHigh