Most useful addon for Firefox Rated 5 out of 5 stars

I use quite a few addons regularly for firefox, most of which just give me more space in my window and eliminate tabs. But the active addon that I use the most is Downloadhelper. It works on damn near anything. I also used to have one-click youtube downloader, but some error in their script kept causing the download links not to come up, yet Downloadhelper continued on strong. I honestly can't express how fantastic this addon is without breathtaking fireworks and a legion of tasty cupcakes.

This review is for a previous version of the add-on (