I hate standing on the edge of a cliff, but I like to climb trees. I don't think I could do the glass floor, but I love flying and flight simulators, and swooping in with Google Earth.
I work on the 25th floor looking down into a construction site, but that verticality bothers me less than looking straight up at the building from ground level.
I'm also afraid upon entering an elevator while carrying keys, papers, cards, that they will fall through the crack and be lost. Hasn't happened yet, though.