Hotel Puerta América Madrid
Inspired by Paul Eluard's La Liberté, whose verses are written across the facade, the owners of this hotel granted an unlimited budget to 19 of the world's top architects and designers. The result is 12 hotels in one, with floors by the late Zaha Hadid, Norman Foster, Jean Nouvel, David Chipperfield, and others. Most popular are the futuristic all-white layouts by Hadid, the elegant black wood and white leather proposal by Foster, and the imaginative re-creation of space by Ron Arad. There's also a well-regarded restaurant and two bars (one on the rooftop), which are all just as impressive in design. The only snag: you'll need a taxi or the metro to get to the city center.