Video Player by Dukt allows you to easily get the embed code for any one of many hosted video services. All you need to do is pass the plugin the URL to the video and it will do the rest.
The plugin supports Youtube, Vimeo, Dailymotion, Veoh, MySpace, Metacafe and Revver. It is available for both EE 1.6 and EE 2 and is currently a free download.
And while I have you here, let me share with you my favorite YouTube video: