I've been to both Madame Tussaud's Wax Museums and I would have to say the one in London is the better one!
This place is so much fun and always a pleasure to visit. You start off in the main forum, where you get to mingle with many super stars, including Brad Pitt, Madonna, Hugh Grant, and many more. As you walk through this spacious museum, you will get a chance to get a nice little scare through the chamber of horror. But don't worry, after the chamber of horror, you are given a relaxing ride on a cute trolley that takes you through a brief history of England. End your experience by mingling with historical super stars like Neil Armstrong and Galileo and watch a nice little education film about space.
Overall, this is a really fun and exciting place to visit!