The only thing that is a minus a bit is that you must have an internet connection working in order to watch the video. Alternative is to save the video to watch it later. This is not as simple as right click - Save, you'll need a downloader to do this.
YouTube Downloader is software that allows you to download videos from YouTube, Facebook, Google Video, Yahoo Video, and many others and convert them to other video formats. Interface is user friendly and minimalist.