Roku is our favorite streaming OS because it has just about every streaming app there is, and the setup is hassle-free. Even though it has moved to include home security in its lineup, the company survives on how well its streaming device platform performs. Chromecast used to eschew an interface altogether, but more recent versions have Google TV built in. Going forward, Google will be focusing its efforts on Google TV and products like the Google TV Streamer. Google TV, formerly called Android TV, is Google's current streaming OS.