YouTube is making another attemp to ban web-sites that allow to download videos from Youtube. Most popular web-site can't download from YouTube anymore, so they offer to use software instead. Also many programs have stopped working recently as well.

Freecorder 4, Jaksta Free Media Recorder, Replay Media Catcher, Jaksta, Orbit Downloader, StreamTransport can still download/capture videos from YouTube.

You can also use Firefox add-ons like Fast Video Download to download from YouTube