Mpv is minimalistic. So far, I haven't found a file format that mpv can't play, and there were a couple that mpv played, but VLC couldn't. When you run mpv, it automatically creates a window of the exact size as the video you're playing (and if the video is larger than your screen, it makes one as large as possible, and resizes the video). One thing I really like about is that it closes immediately after the video is done playing, saving you the trouble. It has a very simplistic UI - when you wiggle the mouse, it displays a progress bar, how far into the video (in hours, minutes, and seconds) you are, and how far you have to go. If there are subtitles or different audio tracks available, it lets you switch them, but that's it as far as the UI goes. You can pause and resume by right-clicking, or pressing the p key. You can switch to fullscreen by pressing the f key. The right and left arrow keys advance and go back by 5 seconds, respectively. Those are all the features I've discovered. If you feel like VLC is giving you feature overload, and all you want to do is just watch the video, you'll probably like mpv better.