I used to be apprehensive about drop towers, but I rode Cliff hanger at FL and enjoyed it, i've been fine ever since, although I remember getting to the top of Drop Zone at Kings Island and thinking 'oh crap!'
Apart from that, the first time on TTD, I was sat in the second car to depart so I had to stay on the Blocks whilst the train in front went around, I remember looking up at the tower structure and feeling very nervous.
I also nearly had a heart attack at AT. I was walking past Nemesis and turned around to talk to a mate, but when I looked forward again I was right up to the chain fence and the the train sped past me at the banked section after the first Corkscrew, I jumped a mile! I should have heard the roar getting louder.