Plug your laptop into it and use VLC. That's the simplest approach.
If you want a dedicated playback system any little arm SBC that has decent hardware accelerated video playback should work well. Something like an RPi 4 can run a basic desktop with hardware accelerated VLC, or you could run libreelec. Look for something modern that supports the encodings you think you might use, it's a drag dealing with choppy playback because you're trying to play an encoding the board doesn't support.
Or you could run a media server like PLEX somewhere on your network and use a Chromecast plugged into the TV as a streaming target. This lets you use your phone as a control device. The simplest setup for this is to just run PLEX on your desktop or laptop and shut the server down when you're not actively using it.