If you guys like the beatles, I highly recommend the LOVE show. got to take in a break in the venetian/palazo shopping area. At certain times they have opera singers or string quartets playing, along with gondola rides IN the shopping center. You willl swear you are in italy! Same thing with going to Paris and checking out the Eiffel tower restaurant.
Plan on a few hours one night in "old vegas" at freemont street. Every hour on the hour they have a show on the massive overhead TVs, plus their are cool bars and casinos there. the golden nugget has several cool fish tanks and one massive one with sharks and etc. there is also an outdoor display for lack of a better word, where they saved all the old neon signs from back in the day and have them set up over several blocks.
I had fun in circus circus, about every 30 minute or so there is a free circus or trapeze act. They have a fun little area towards the back with a couple of roller coasters and other rides.
The roller coaster at New York New York is fun! make sure you use the lockers to keep stuff in. On the double loop my cell phone, keys, etc. came out of my pockets - that was a first!
There are lions and cubs that your gf will oogle at the baby cubs for awhile at MGM grand. Excaliber has the medieval times, jousting knights shows with wenches serving you.
Ferrari dealership in the wynn, pretty much every casino has cool stuff in or near the gambling area and lobby/check in areas - plus most have a feature like dolphin park, aquarium, gardens, fountains, etc. Treasuer Island has an outdoor show every hour. We usually spend most of our time just wandering around the casinos.
Keep an eye on the shows, you never know what comedian, band, etc. may be there. there are several smaller casinos on the strip that usually have lower buy in and better odds.
I usually bring enough cash to plan on losing a hundred bucks a day gambling. If I reach my $100 limit then I quit that day and find something else to do. They bring you "free" drinks while you are gambling. Usually I average losing $50 a day over the course of a trip, which I call a break even with the drinks and potential for comps for free meals or discounted rooms.
It really is like an adult Disney land to us.