Just went on the bus tour to the Hoover Dam and we had a blast. Our driver's name was Willie and he entertained us all the way to our destination. He kept us safe and made sure we drank water! :)
We took the tour as part of the Vegas Go Pass (which included the ride to the damn, a two hour stay to walk about freely and visitor's center). My pass did not include a tour of the generator, which was optional.
Great company. My husband left his cell in the bus and Willie had it ready for us to pick up at the desk within an hour of being dropped off at our hotel.