I know a lot of people keep saying Kodi this, Kodi that, but I think Nova Video Player is the best Android TV player right now because it is faster than Kodi because it is Android native, simple to use, plays everything, and connects to media shares easily. Like Kodi, it is fully open source and is a complete media center minus the python addons so if you just need to play videos over your network, give Nova a try.
You can find it on the Play Store and visit their subreddit at /r/novavideoplayer
You can also test the latest v6 builds with all the latest features at https://github.com/nova-video-player/aos-AVP/releases
The dev says v7 will get a "new look" if you guys think the current look is not enough for you.
Any questions? I'm not the dev but I can help anybody who needs it.
When i want to use something simpler than kodi i usually use VLC for Android.
I do not see a reason why this would be better.