Considering I have a pretty bad fear of flying, I actually really enjoy roller coasters. Alton Towers is probably the best one in the UK, despite recent incidents.

http://www.bbc.co.uk/news/uk-32985384

That reminds me of a water slide I went on at the Palm Atlantis in Dubia. You stand up in a tube, you are told to cross your arms and legs then the floor just opens and you drop vertically a LOOOOOOONG way down this dark tube into a pool of water. I cracked my ankle on the way down and it was just generally unpleasant.

I should have known when there was no queue for the ride.