Be sure to check out the downtown experience, after dark. Its cheap (free), and you can catch the double-deckers they now have running up/down the strip for $2 each way.
Also cheap, do the walking thing up/down the strip to see the various free events...the volcano, the high seas battle ship sinking, the water ballet at bellagio.
I really enjoyed Blue Man group. Interesting and entertaining show.
Check out the various buffets. Various prices and themes (seafood, bbq, etc.)
We always pick up the local listings and read through them when we first get there to help plan how to spend our time.
AND, I'd agree that if you have the time, do the Hoover experience. Its a really neat Dam tour! You can get some good Dam pictures and ask a lot of Dam questions (lol, stole it from Lampoon's Vegas Vacation...couldn't help myself!)
Plus, they will extend you an invitation allowing you to come back anytime to visit your money....<grin>
My wife and I went for the first time 7 years ago. Raising kids ,taking care of buisness and actualy took the kids on our first trip. We go 3 times a year and the kids haven't been back. Going out in 2 weeks to check out the Wynn.
See a show for sure and if you haven't already ,TRY to make a dinner res.
If you don't gamble much go down town to some of the cheaper tables and get your feet wet. Depending on where you are staying the tables can jump up pretty quick. There is a little casino next to the Venition, Harrahs and in front of the Imperial. Its a dive, but its cheap and fun.I think its called Casino Royal. Good place to learn craps. Get ready to have everyone and their dog put there hand out for a tip. If you're staying on the strip use the tram that runs from the MGM all the way down the stip. Tried to walk everywhere the first couple of times: to far, to hot. If you want to hang out at the pool get down early and save a spot, they go quick. Have a great time and let us know how it goes.
In addition to what has already been suggested, ride the roller coasters at New York,New York and the Sahara. See "Big Elvis" at Bill's Gambling Hall. A dusk helicopter flight along the strip is $79.00 a person. Go to the top of the Eiffel Tower at Paris Hotel. Check out the Forum Shops (shopping) in Caesars Palace.
If you go downtown, consider the "Deuce" double level bus that runs to all the hotels along the strip. It takes a little longer to run the strip to downtown (Fremont ST), but it's only 2 bucks a person, compared to the taxi ride which will be around 20 bucks.
We are seeing Blue Man Group, but I hear all of the Cirque De Soliel show are great, particularly "O", and "Love".
I like the Shark aquarium thing at Mandalay bay. It's a little expensive though. Around $20.
The car collection at Imperial Palace is cool too. Sign up for the player card and ask for a coupon.
Bust out some big cash for a dinner at one of the high-end places. Its a great experience.
If you have a car go to Bass Pro... well I usually do anyway. Why not... its free admission!!
If you have wife or g/f with you, we also drive out towards CA to a "factory outlet" mall and the forum shops at Ceasars is usually on the agenda. The deal with shopping is that I don't mind as long as she buys me drinks!!
I would say just wander as much as you can. Each place is different.
second the comfortable shoes and if there is a female traveling and she wants to look "CUTE" in the words of my wife forget that. You will end up carrying her 5 blcks with her shoes tossed in a trash can.
Bellagio Water Show-Free all day
Treasure Island Pirate Show-Free at night
Mirage Volcano-Free at night
Mandalay Bay shark tank- $15 or $20 per person
Shopping at Caesar's Forums, Bellagio, or Mandalay Bay shops
Golf outside of Vegas at Paiute- Beautiful courses and cheaper rates now
Any of the clubs/bars- Rain, Ghost Bar, Studio 54, Drai's, Rum Jungle, lots others
Most hotels have signature restuarants that are all excellent.
Spearmint Rhino- "Adult entertainment" & completely insane..bring your wallet.
"Rehab" at Hard Rock pool on Sundays
Mandlay Bay wave pool
Top of the needle of the Stratosphere- I hate heights and still thought it was great.
Freemont Street light show at night, plus you can stop by the old casinos.