Here are some of my favourite sites.

Theme Park Officials
Thorpe Park Visit the official website of the Thrill Park
Chessington World of Adventures Visit the official website of the "fangtastic" family park
Alton Towers Visit the park's official website
Parc Asterix Visit the official website with bonus' such as music, downloadable on ride video's and games

More

Disneyland Resort Paris The official guide to Disneyland Resort Paris
Disney World Resort Florida Or why not visit the official Website for the Disney World Resort Florida
Cedarpoint Why not visit the official rollercoaster capital of the world website
Theme UK Visit a website dedicated to Thorpe Park and CWoA which also has a Roller Coaster Tycoon section
Chessington Uncovered A website totally dedicated to CWoA
Roller Coaster Database A fantastic roller coaster database with virtually all the roller coaster's you can think of
Vekoma Ride Manufactoring Want to know the technical way's of some of your favourite roller coaster's or download some video's of them click on the link