Spent last weekend at Mandalay Bay with a group of 12 celebrating a friend's milestone birthday. One night we had a party in my suite (small suite) with catered appetizers from Border Grill and cupcakes from Retro Bakery. I was a little concerned about planning a party from 300 miles away on less than one week's notice, but everything worked out great. The special events manager at Border Grill was super helpful with figuring out what quantities to order and which dishes would hold up best at room temperature. Everything we ordered was delicious (most of the items aren't on the regular dinner menu) and nicely plated on colorful plastic platters that we just had to return the next day. I aslo highly recommend Retro Bakery to anyone looking for celebratory cupcakes in Vegas (they do cakes as well). They delivered to the hotel at exactly the promised time, and the price was reasonable (less than one would pay for Sprinkles or Crumbs, even with the $20 delivery charge added on). My favorite flavor was the pistachio, followed closely by the raspberry/lemon. Butterscotch, apparently their most popular flavor, was a little one note (that note being sweet) even for frosting loving me. I didn't get to taste any of the chocolate varieties but the kids and chocoholic adults were very pleased with them.
We also had a late dinner at Lupo, Wolfgang Puck's Italian restaurant. It doesn't get mentioned here very often, but it worked well for our situation with a large group, some of whom wanted a multi-course meal and others more of a snack. Portion sizes are generous - individual pizzas too big for any one person to finish, giant plates of chicken Marsala and veal Milanese, big bowls of mussels, etc. Nothing earth-shattering, but well-prepared quality ingredients all around.