Grand Canyon, Hoover Dam, and there's quite a good discount shopping outlet just outside town (near the airport). And a wonderful dinner at Joel Robuchon at MGM Grande (yes, it's expensive, but it's Michelin starred). That's it, unless you're crazy enough to gamble. about 5 years ago
My top experiences to offer would be:
1. Helicopter trip over the strip at night -if you're as lucky as I was, the Bellagio water show will go as you are in the sky. I've also found it reasonably priced (about $70-$80)
2. Fremont Street - old school and cliche. Love it!
3. Go to the very top of the Stratosphere - there are rides for daredevils, or just a great photo opportunity for anyone else
4. FYI - best view of the strip is from Ghost Bar at the Palms hotel - 55 storeys high and set slightly behind the strip so the view is amazing!
5. Pool Party at any one of the hotels
If you feel like keeping cool and like the thrills of waterslides, Wet N Wild Las Vegas is now open too.
If time permits, a day trip to the Grand Canyon is always a must. hope this helps! almost 5 years ago