I have never..... - But would like to......

[Arthur Dent]

Whitewater rafting (closest I did was rafting down the deleware.)
Spelunking (exploring caves. Not like Howe Caverns, but the ones where you have to crawl through a crack in the wall to get into.)
Flown in a plane going supersonic
Been in a hot air ballooon
Bungee Jumping
Deep sea fishing (where they have to anchor you to the chair and poor water over your reel)