Far and away the best system to wirelessly stream digital music to any room in your house. Attach a Sonos player to any stereo in your home, or to a pair of speakers, and control them via the Sonos remote. (Or forgo the remote and use the free Sonos application on your iPhone.) Play your MP3s or get Pandora and thousands Internet radio stations and fill your life with music for free. ($350 per box)
—Josh Quittner