Located in one of the most spectacular piazzas in the city, this is the It-Girl of Rome's hotel scene, where high-rollers come to party by the rooftop pool and pamper themselves in the spa. The spacious guest rooms are predictably luscious in an uptown way, with oh-so-silky linens and gilt-framed mirrors; some have views of the fountain in the piazza outside. Unlike its naughty younger brother the Aleph, the Exedra is a model of Neoclassical respectability, but there's a glint of cutting edge in the paparazzi-inspired (and inspiring) Tazio brasserie. Why stay here, rather than at the umpteen other expensively elegant hotels in central Rome? You can think about it while you lounge by that rooftop pool.