You might provide a few more requirements like price range and features you would like to have:
* Computer/USB based solutions (including raspberry pi), just install linux, run MPD or XBMC or do stick with Windows/Mac
* SB competitors: Airport Express, Apple TV, Roku, Sonos and even blu-ray players and gaming consoles can play back audio. (not to mention your TV might have this feature)
* Full custom players like Olive, sooloos, Bryston BDP and Sim's MIND solutions.