Great show! If you are in Vegas for anything, make sure to add this show to your visit. What is especially great about the Blue Man Group is that they include the entire audience in their performances. Just make sure not to sit too close to the front of the stage if you don't want to get hit with any liquids since they have a segment of the show where food/liquid is used as a prop. If you are shy, you won't want to sit near the front rows either, since they make it a point to walk out onto the chairs to meet the audience up close and personal. Be warned.
What surprised us most about the Blue Man Group show was the music. It was great when we were there. When we went, they were playing live at the Venetian, and began the show with music and ended it in the same way. We liked it so much that we purchased the CD at the time, entitled "Blue Man Group: Live at the Veneitan, Las Vegas." They have a different show now, but I would not be surprised if the music was just as good, if not better.
The music, the humor, the weird/creepy factor. All of it makes seeing the Blue Man Group a must when you are in Vegas. They are a classic Vegas show, well worth the ticket price.