Well there's the Nexus Player if you can find it available anywhere, or you can wait for the Xiaomi Mi Box to arrive later this year. It'll probably be about $100.
But you're not asking about either of those two devices. You're actually wanting to know about the best TV box that runs the Android OS and not one that runs the Android TV platform. For that, you'll need to ask /r/settopboxes or /r/AndroidSetTopBox.
Sgt-JimmyRustles
Well the MiBox might be worth it when it comes out. However, the only box I can recommend is the Shield which does not hit that price point of $100.
Andrroid
Now? Nexus Player if you're lucky. Otherwise, get a new roku stick or roku 2/3 or a fire tv.
Well there's the Nexus Player if you can find it available anywhere, or you can wait for the Xiaomi Mi Box to arrive later this year. It'll probably be about $100.
But you're not asking about either of those two devices. You're actually wanting to know about the best TV box that runs the Android OS and not one that runs the Android TV platform. For that, you'll need to ask /r/settopboxes or /r/AndroidSetTopBox.