If you're looking for a good scare, modern roller coasters can deliver. As well they should: Some of the nastiest cost up to $25 million to design and build. With help from the folks at the Roller Coaster Database, Forbes.com assembled a list of the 10 most blood-curdling of the bunch, weighted by top speed, height and drop, in that order of significance.

Experience The Most Blood-Curdling Coasters