The Liberace museum is interesting. If you have a car check out Red Rock Canyon (On the way to Pahrump). If you like roller coasters, take the short drive to Primm and ride the coaster there, it was the biggest, fastest, tallest in the world (Or some such nonsense) for awhile. Hoover Dam is still worth a visit if you have never seen it, but the tours available today are nowhere near as interesting as they once were (A casualty of 911). If you have a limited budget, just rent a car for one day or maybe two (1 or two days are ample time to take in area attractions not on the Strip, Downtown or in the immediate vicinity). And if you want more suggestions, check out a website that specializes in travel like
www.fodors.com. You'll get tons of suggestions there. Enjoy your trip.