Not quite sure then...
I would suggest getting a Media player and just leave that connected. A lot of devices don't have great codec support so it depends what kind of video files you have.
Western Digital has excellent support, though they're device WITHOUT the hard drive doesn't support Netflix.
http://www.wdc.com/en/products/products.aspx?id=1270
(you can attach a USB hard drive, connect to WD MY CLOUD or similar via local network, or connect to PC... connecting to PC can be a bit tricky to set up)
ROKU 3 has only basic support of video/audio codes.
There are some x86 (same architecture as desktop CPU) small devices you can put KODI-Linux on which work well. Though probably no Netflix support through the KODI interface.