Try a dinner at Battista's "Hole in the Wall." It's Italian food, reasonable cost, and the cappaccino at the end is worth whatever you pay for the dinner (the cost of dinner includes salad, bread, cappaccino, etc).
It's on Flamingo, just before LV Blvd, across from Bally's in a little strip-shopping center.
There's an accordian player that circulates (for tips), he's about 80 years old, and MAYBE five feet tall (probably more like four-and-a-half). He'll ask you where you're from, then try to do a tune that relates....one time we told him we were from Orange NJ (really from Chicago) ...knowing that there's no tunes/songs about or relating to Orange....so he thought for a couple seconds, then says " Well, there's always the Tarantella (SP?)" and plays it, takes the money, and moves on.
The "Star Trek Experience" at the Hilton (old International) is pretty good if you're a Trekkie, there's lots of paraphenalia from all of the movies and TV shows, and the usual collector junk at the end (the food at Quak's isn't too bad, and only a little overpriced).
The "LasVegas Experience" is pretty slick, at least the first time or two you see it. It's a four block long canopy of lights tied to a megawatt of eight-channel stereo that covers most of the old "Glitter Gulch" downtown...pretty decent light show (and it's free).
If the weather is good for strolling, then talk to the desk at your hotel and get the schedule for the following (free, from the street, gotta see it at least once ..):
Going North from Bellagio: (just South of Flamingo on LV Blvd ("The Strip") - The Dancing Water show at Bellagio, The Volcano at the Mirage, The Pirate Show at Treasure Isle.
Luxor has a "from the street" show, if you're in the neighborhood, stick around to see it, but it's not worth a trip just to see it. Excaliber, NYNY, MGM Grand ...all do something, but aren't worth the trip (IMHO).
The helicopter rides are pretty slick if you have the cash to spend, you see the whole town from above.
The restaraunt at the top of Stratoshpere is very expensive, the food is a little better than "OK," and it revolves at one rev per hour (there's also a roller coaster and seat-drop at the top...1150 feet agl).
If you want to see the sights from "way up there," the Voodoo Lounge at the Rio has an open-air deck 51 stories up, (there's a dress code and a cover).
There's other stuff (the white tigers @ Mirage, the Appian Way in Ceasar's, the gondola rides at the Venetian ...) you can literally spend days walking / riding from place-to-place and never drop a dime gambling (personally, I've seen all that stuff (many times), and would rather gamble....).
Personally, my favorite place is The Rio. I've stayed at just about all of the main houses, and I prefer the Rio (though it has definately gone downhill since Harrah's bought 'em)...YMMV. The Monte Carlo is a very nice place too., so's the Mirage ....lots of nice places...
If you do gamble, take the time to join the "Player's Clubs" at every place. The card they give you allows them to track your play (to get a "rating"). It takes surprising little play to start getting offers from them for cheap rooms, free entertainment, etc. Get the cards & use 'em ...collect 'em....
Be careful if you wander off the strip or downtown...there are lots of bad areas in Vegas.
Enjoy your trip, good luck!
Scott