I'd love to try a bobsleigh! I used to have a kamikaze (not the actual meaning!) nickname when I was younger as used to do lots of rock climbing (abseiling without a safety rope, prussiking etc...) and was an RAF cadet do did shooting and basic flying and gliding training and had a bit of a thing for aerobatics save the main part of a stall turn (dip down then go straight up vertical then twist and come down in a spiral - the g-force smacking you in the stomach in the twist is a killer seeing as you have to try and keep the plane flying and all). I'd love love love to go in a fighter jet!
Did various other stuff, gorge-walking, kayaking, canoeing etc...
Always fancied doing a parachute jump, white water rafting and having a go in one of those big ball things though I think fear and realisation of mortality has set in more as I get older, that and hobbling about with a walking stick anyway :)
Bungee jumping doesn't appeal though, I have a thing about my ankles being fixed (similar with snowboarding to an extent) and would rather go down and stay down, not so keen on the boinging bit. Bit like rides I guess, would rather go on a ridiculously loopy rollercoaster than one of those things that shoots you up in the air.