You know all those video files you have that can't play on your Apple TV? VLC just fixed that problem, assuming you have a fourth generation Apple TV. Their new native app streams content from local network including video and audio in most any format you can think of. It uses a Web interface to get files over to your Apple TV and can store files locally for playback. Cloud support for Dropbox, OneDrive, and Box is in testing now, so you'll have even more flexibility in where your media files live soon. VLC for Apple TV is free.
Check It Out: VLC Player Comes to Apple TV