Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Online Convert - Convert files like images, video, documents, audio and more to other formats with this free and fast online converter.
Video DownloadHelper - Browser extension to download videos from the Web
Wide Angle PDF Converter - Convert PDF documents to Word, PowerPoint, Excel, JPG and other formats!
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
CometDocs - Free online conversion service. Possible to determine unknown file format too.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.