I've never been to any theme parks other than Disneyland which was years ago, so I would say Disneyland as well.
The "Roller Coaster Capital of the World" Cedar Point. I've always wanted to go to disneyland just so I could punch a guy in a Mickey Mouse suit though
how could you not put down drayton mannor in the midlands? with the stand-up roller coaster and the stand-up drop ride, and storm force 10
I must have been about 8 last time I went there... no actually I went on a school trip there once, cant remember how old I was but it was in the last 10 years.