Go to the startosphere tower and ride the coaster on top. Eat lunch afterwards!
Here is part of a list of 100:
1. See the white tigers at Siegfried & Roy's Secret Garden: The Mirage
2. Visit the dolphin habitat: The Mirage
3. See flamingos and African penguins: Flamingo Hilton
4. See the brilliant collection of parrots: Tropicana
5. Take in the best show in town from the entertainer of the year: Danny Gans at The Rio
6. See the classic car collection: Imperial Palace
7. See daylight at night: downtown Las Vegas after dark, the $70 million Fremont Street Experience
8. See the world's largest atrium: Luxor
9. Visit the glitziest museum in the world: Liberace Museum (1775 E. Tropicana)
10. Ride the tallest and fastest roller coaster in the world: Desperado (Buffalo Bill's, Primm, Nevada)
11. Ride the highest roller coaster 1,200 feet off the ground: on top of the Stratosphere (Las Vegas Blvd. near Sahara)
12. Ride the fastest moving straight up and down ride: Stratosphere's Big Shot
13. View an exquisite collection of fine art: Bellagio
14. Submerge yourself in a magnificent garden of fragrance and color: Bellagio
15. Ride an indoor roller coaster at amusement park Grand Slam Canyon: Circus Circus
16. Visit Madame Toseau's wax museum: Venetian
17. Love hamburgers and Harley's?: Harley-Davidson Cafe
18. Go face to face with sharks: Shark Reef (Mandalay Bay)
19. Cant get enough neon: Neon Museum (look for the giant neon horseman at Fremont Street Experience)
20. Watch the dragon battle against the magician: Excalibur's moat
The whole list is here
I went there, and although I didn't stay very long, I just winged it. Just start walking and something will catch your eye, or you could ask the
employees at your hotel what is the really neat stuff they don't advertise.