Mandalay Bay or near by - top picks - 3 nights
Any restrictions on type of food or budget ? I agree w robuchon, and I suspect (having been in Chicago) that Yushon would be great. I'm less excited about Mix although love it for a beverage. Also recommend press at the four seasons for a low key beverage.
I like a fair number of the choices at city center, including twist at the mandarin and sage at aria, as well as docg (more casual ) at the Cosmo.
If the sky's the limit,I would probably do twist, rubochon, and Cut (for a Vegas steakhouse experience). You will be poorer, and your cardiologist will be richer, but it will be fun!