Only time I was in Vegas was a few years ago, bookends of a trip to Bryce/Zion.
I'm not a gambler, but glad I got a small taste of the strip. Wife was horrified, I was amused. Saw the Cirque "O" show and while it was good, we both thought it was highly over-priced and over-rated.
Off the strip, others have mentioned Red Rocks and skiing, I'll put in a good word for the Valley of Fire. Hot as f*ck but jaw dropping.
On the flight home my son (9 at the time) is drawing vacation pictures and wifey asks what it is and he says it's a girl in a bikini. She asks where he saw that and he looks up incredulously and says "Mom, there were a lot of bikinis in Las Vegas...A LOT!!"