I met up with my mother (who goes several times a year), my sister coming in from Australia and my brother who Las Vegas is the antithesis of everything he believes in.

We (my brother and I, that is) had the most fun at the pinball hall of fame
http://www.tripadvisor.ca/Attraction_Review-g45963-d620854-Reviews-Pinball_Hall_of_Fame-Las_Vegas_Nevada.html

It's not much to look at from the outside, but we had a blast. The owners donate huge sums of money to local charities.

We were also impressed with the Las Vegas Springs Preserve
http://www.springspreserve.org/. A very nice break from the bells, whistles and lights.

The Atomic musuem
http://www.nationalatomictestingmuseum.org/
Was very interesting, but very content dense. You can't do it justice to try to see it all in one afternoon. I think the gift shop should have had mushroom cloud salt and pepper shakers, but no such luck.

We saw Absinthe which was a bit crude, but really good. I got dragged to the Holly Madison peep show (my brother begged off - smart). It was really, really, really dumb. Beyond dumb. I am glad I did not have to pay for my ticket, but I want those 2 hours of my life back.