Go to the Red Rock Canyon, Valley of Fire, the Hoover Dam, the Spring Preserves and or Death Valley. Lots of other places as well such as the Sunset Park, and there are numerous other parks all over the city.
A week and a half left..... soon there.... Man I am going to enjoy Me, Myself and I for once! 
What are must sees and dos? Restaurants, shopping, poolparties and ENTERTAINMENT! 
Private pool parties and topless pools are always a hit.
Moorea at Mandalay bay is awesome as well as Venus at Ceasers and Bare at Mirage.
Restaurants area dime a dozen , the new SLS has some fabulous new additions .
Some of my favorites are Umami burger , Carnevino at the palazzo , Prime at Bellagio and Joes seafood at the forum shops.
Shopping , crystals at city center for high end along with the Wynn , forum shops and the outlets are great ,
the Fashion show mall on the strip will have most stores covered.
Hope my short list helps , enjoy your stay.
April
...the LADIES!! And AprilLuv can serve up some memorable moments! Jest sayin'....
Just got back last month from Vegas. No place like it.
See the water show at Bellagio. Walk through the grand opulence of The Wynn. The Cosmopolitan is a great casino/hotel to walk through and check out Chandelier bar.
You have to do see the Fremont St. experience. It's crazier than the strip and cheaper.
Planet Hollywood is built into a mall if you want to shop. Get into a poker tournament. The Flamingo has a tournament every few hours for $50 buy in if you want to start small and try your luck first.
New York has a fun casino floor with a loud center bar. Coyote Ugly is there too.
There are literally too many burlesque topless shows to name them all. I went to the Britney Spears show instead.
Go to the Red Rock Canyon, Valley of Fire, the Hoover Dam, the Spring Preserves and or Death Valley. Lots of other places as well such as the Sunset Park, and there are numerous other parks all over the city.
Thanks a lot for the great recommendations so far!! I know I will have a fab time!
For restaurants try Bartolotta at the Wynn, best langoustine and the ambiance is romantic. Lotus of Siam for amazing thai food, Cirque at Bellagio for best souffle and my favorite bar is at the Mandarin Oriental gorgeous view of the city.
As far as activities renting a boat and exploring Lake Mead is fun, If you have transportation and want to escape the heat the drive to Mt Charleston is nice I do it on my motorbike. Also even as a local I really enjoy going down to exotics racing its not too far from the strip and it's so much fun you can really let loose on those cars.
Either way i'm sure you'll have a fabulous Vegas trip
coursing through the casino. The Mirage has 2 dolphin pools where the trainers come out very regularly and the dolphins come to the side of the pool. $15-20 and you can stay there all day. Best deal on a show is the Mac King comedy/magic show at Harrahs during the day. $12.99 a ticket or even free if you ask the conciere (sic) or go outside to the bazzar (sic)where they hand out free show tickets.
I go there 2 or three times a week. They have 35 massueses, and about that may tables. You can ask for male or female to massage you. A third of clients are women 2/3 men. Refloxology, great pressure. Whole body (almost).