I use old Intel nucs or just mini PC's in general put debian or whatever you want on them paired with an Amazon wireless keyboard and trackpad, I think I searched wireless pc remote on Amazon, and blamo you have a media centre pc... if you use plex they have a desktop app or a media center version of it you you can boot into on boot which is great because I don't need to launch it everytime. Plus when I press any button on the keyboard it wakes up the TV and pc seamlessly... honestly it's fantastic, I have a smart TV that cost way too much because I exclusively just use the pc connected to it