Went to Blue Man with a group of 4. We were able to get tickets at 40% discount online (via smartervegas.com) and sat in the middle of the front row in the "poncho" section.
The show was very entertaining and funny, the music was really great and the glow in the dark band was pretty awesome. It's definately a little weird and I can see how its not for everyone. If you are debating whether you want to go and think you'll like it, you probably will. If you think it looks dumb, well... plenty of other shows to see if vegas. A nice touch is how the Blue Men (and the band) stick around after the show for pictures, autographs, and other such things.
Although I liked it a lot, there were a few things that I was less enthused with... the audience participation segments seemed to be pretty clearly plants which was kind of annoying because they made a big deal out of searching the audience for the volunteers (though their mannerism climbing over the crowd are entertaining).
As for those wondering about the poncho section, there is this segment involving twinkie eating, lets just say avoid the front row if you don't want to get messy. The second row seemed safe enough but in the middle of the front row I was covered in goo and plenty of it got under the poncho. I needed a shower and change of clothes after. Unfortunately, it was only about half way in the show so I sat with "twinkie" (later discovered to be banana mush) in my hair for about 40 minutes. I thought it was funny but I can see people being annoyed by it. The "paint" used didn't really get off the stage at all, I think I got a drop or two on me.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.