The Campbell Apartment is where Serena and Nate first did it on Gossip Girl, and if you're lucky enough to have the bar for a private session like they did, you can probably wear whatever you want--or nothing at all. For the rest of us trying to inject a little glamour into our daily grind, however, an after-work cocktail in a rich man's former study is sufficiently staid and fabulous. But don't even think about sipping a cool glass of champers if you're not appropriately attired. Same goes for the sky-high Mandarin Oriental Lobby Lounge: If you want the coveted perch over Columbus Circle, denim and sneaks are a no-no. Dress like a journalist and you'll be relegated to the adjacent MOBar. It also features windows 35 stories above ground--only these look out at the building next door.