The Chandelier is one of those high end lounge/bar inside the Cosmopolitan.  With 2.5 floors, there's plenty of chairs to sit and mingle and lots of servers to fulfill your needs.  I personally feel Vesper (near the check-in reception) at the opponent end of the building have slightly skilled bartenders, Chandelier's service is more than 5x faster than Vespers.\n\nSince Chandelier has highly skilled bartenders, you don't need to order well drinks like coke & rum and redbull vodka.  You can start experimenting with better and tastier drinks like Whiskey Sour (my favorite), Old Fashioned (Ryan Gosling drink in Crazy Stupid Love), or any other great drinks you wouldn't normally order at a club since those bartenders suck.