ARIA, Las Vegas

It takes a lot to make waves in Sin City, but Aria did it in 2009, redefining the skyline with its minimalist, curvilinear glass towers housing 4,004 rooms, 17 restaurants, nine bars, a casino, spa, pools, and resident Elvis-themed Cirque du Soleil show. The accommodations, with floor-to-ceiling windows and iconic masculine Vegas style, have beauty and brains: upon a guest's first entry the curtains open and the TV switches on to reveal customizable room controls for lighting, temperature, music, and wakeup signals. Also impressive is Aria's LEED gold certification. Ample natural light, wood, and stone throughout add an uncommon organic quality here-proof that green can be sexy.