YouTube-dl: Open-source YouTube downloader
The tragedy of this software (and many like it) is that despite working exactly as advertised, easily and with a lot of features, because it's a quiet open source project without any SEO rigging it will never appear in page 1 of any searches by laymen trying to download videos ("save youtube to hard drive", "download youtube videos" et al).The amount of crapware I've had to remove from family member's PCs just because they wanted to save a video is ridiculous.