The $10 Echo
One of the more impressive things about the Echo is its far-field mic. I've used a lot of different voice recognition technologies, but Echo blows everything else away in terms of being able to speak in a normal voice <i>from the other side of the room</i> and have it still understand you. The actual intelligence behind the service may be lacking (or at least behind some of the competition), but for a general-purpose home application, the mic (in my opinion) is a significant part of Echo's reliability and success.