There's also a really big cactus garden by --- I think it's Mrs. M's Chocolates. It's a very nicely maintained botanical garden.
Just off the Strip at the Hilton is a Trekkies' wonderland. We were too cheap to take the 'ride', but did enjoy looking around in all the Star Trek shops.
The Morman Temple. Great view, espically at night. Drive north on Las Vegas Blvd. to Bonanza, turn right on Bonanza and drive about 6 miles until you see the temple before you.
Walk ten minutes off of the strip and you'll see where all the garbage goes. The strip is amazing, so clean and yet there are so many people. Walk a bit, and you'll see something different.