free media Video Video Player

What's the best free video player for Mac?   

Updated 21 Jun. 2019

Although Mac has its built-in video player- QuickTime, some type of videos can't be played by it. I'am now using Cisdem Video Player- a free app that supports 4K video playback. Any free video player that is better than this one? If no, I will continue to use Cisdem Video Player.