Mine are NoScript: Best buddy in the whole wide web, nothing runs scripts unless I explicitly allow them to. Easy Youtube Video Downloader: Love this thing, I can download any video on youtube, from the actual video's page itself, in whatever quality and format is available. I can't live without this addon, just cant. Download Statusbar: An asthetic choice, but has some uses. I can manage all of my downloads from a status bar on the bottom of FireFox window. I can pause, cancel, open the containing folder, etc. Personas: Love it for asthetic reasons, and because I don't like using regular themes. Foxkeh Canoe is my current one. Youtube to MP3: Allows me to convert any video to an mp3, HQ or regular quality.