There are 1 previous version of this script.
// ==UserScript==
// @name YouTube Video Only
// @namespace http://po-ru.com/
// @description Fill the screen with the video, and hide everything else.
// @include http://*.youtube.com/watch*
// ==/UserScript==
(function(){
GM_addStyle('body { height: 100% }');
var video = document.getElementById('movie_player');
video.parentNode.removeChild(video);
video.width = '100%';
video.height = '100%';
document.body.innerHTML = '';
document.body.appendChild(video);
})();