Back in 2011 the wife and I took the tour and we had a blast. We interacted or took pictures of just about every statue in the place.
At the time Madame Tussauds had a walk through "Haunted House" that was quite tame by my standards. Walking through this Halloween attraction one person jumped out at us, scaring the daylights out of my wife as I giggled. (see picture)
Personally I felt that the "Haunted House" needed more statues of persons known from horror films. A Freddy Krueger, Jason Voorhees. Someone of that sort. I was looking for Lon Chaney and Vincent Price. Instead we got a guy in a bad costume and make-up.
I posted all the pictured on Facebook and wow did people think we (my wife included) really met all those celebrities. Yup, movie stars, I've met Presidents, Oprah, Racing drivers, and a rap star, a adult movie star and yes my wife was with Hugh Hefner!
Although I didn't care for the Haunted House I would still strongly recommend going.