While I certainly appreciate the engineering marvel that is Hoover Dam, I really just didn't see the need to stand around and stare at it for hours! I didn't even spring for the $8 to go inside the museum. If you come to Las Vegas, you're almost obligated to go see it.
(Click on photos to enlarge.)
There's a very nice Visitors' Center
This is a beautiful statue
Supposedly, if you rub the toes, it brings you good luck
Upper Pic: From the Dam, you look out at this bridge
Lower Pic: Hoover Dam while standing on the bridge