* Late night pizza by the slice at Secret Pizza in the Cosmopolitan is pretty good.
* If you do the Stratosphere go for lunch or dinner. You get a free ride up and in our case the bill was cheaper then paying to go up.
* Ellis Island has the best dinner deals IMHO. Not fancy, but the steak was good. Also they brew their own beer and serve it for $1.
* MGM Grand has a Sigma Derby, mechanical horse racing game from the 70s. Cocktail waitresses are around often with free drinks.
* I've been to most of the shows. My favorites are Love, La Reve, and Lion King.
* When you go to the shows ask the usher if there are any upgrades available, often they are free or really cheap.
* I like the pinball Hall of Fame. I spend 4-5 hours there on almost every trip.
* Rent a car and go to Red Rocks (30 minutes) or Zion (3 hours).
* Free bands in the bars or on Freemont Street can be pretty good.