I moved to Las Vegas from Phoenix, Arizona about 7 years ago. I have driven back and forth between Phoenix and Vegas more times than I care to count. This was long before the Pat Tillman Bridge was complete, so I have seen and been to the Hoover Damn many, many times.
It is an absolute marvel. I still remember the first time we drove thru here and I saw the Dam for the first time. I've never had the pleasure of taking a tour, but maybe one day.
It is definately best to check it out at night when it is not busy and its actually quite beautiful and peaceful.
If you've never been here, you owe it to yourself to see it at least once.
5 stars.