MacroTube is a free plugin for Windows Media Center that lets you watch Youtube, and DailyMotion videos in Media Center.
MacroTube installs directly in Windows Media Center as a plugin. Once installed, you can search for Youtube videos directly from inside Media Center.
Interface of MacroTube is really pretty, and it makes it lot of fun to watch YouTube videos in Media Center. If you want to show update status of your media center on Faceook and Twiter, you can use Media Center Status Application.