The best "casino" arcade that I have been to is the upstairs one on the second level at "Circus Circus". It's kind of above the front of the building, but to get to it, you have to go into the main open area where the trapeze is and then double-back up the stairs and around the midway area. You also can't go wrong with the Gameworks, particularly if you like Sega games. Across the street from there is the New York, New York which used to have an ENORMOUS arcade upstairs, but for some reason they cut it's size substantially a couple/few years back. You will find a couple of curiousities there (like an MTV Drumscape -look it up), but mostly newer games. I have not been to the pinball museum, but it sounds like a must-see.
For food, the best steak in town is at "Prime", which is located in the shopping area of Bellagio. The last time we ate there, I had a REAL Kobe steak, and it was insanely awesome. Forget about "American Kobe" or other imposters. The REAL DEAL gets flown in from Japan, costs big bucks and will NOT disappoint. Expect to pay $25 Per OUNCE of meat, but there will be no fat whatsoever. If you like Thai food, then you MUST go to the world famous "Lotus of Siam". It is a hole-in-the-wall joint, in the middle of a strip mall in a "questionable" looking area off the main strip, but it is EXCELLENT...
Lee