Backblaze earned praise from many of you for being easy to set up, even for non-technical people. It's built for people who want to get their data backed up, without being forced to search for error codes and cryptic status messages whenever something goes wrong. To that point, Backblaze backs up just about everything on your system. You get some control over what's backed up and what isn't, but the point is to be fast, easy, and hands-off, so everything on your system—documents, music, video, external drives you have plugged in, just about anything. Instead of telling what they do back up, Backblaze actually has a special page dedicated to what they don't back up instead. Backblaze offers unlimited storage for your backed up data, and while by default it only backs up files smaller than 4GB, you can bump that up if you need to. Like other online backup services, it runs in the background, backing up your data all the time (or when you schedule it to, if you prefer), and your data is encrypted so only you have access to it. It supports Windows and OS X, and is smart enough to de-dupe data, do incremental backups, and keep backup processes low on system resources. You can read more about Backblaze's features here.
For this software, you just need to copy the YouTube link and paste it directly into the box that’s labeled for the link. Then you get to choose the format that you want to download it into. You’re going to need to download their specific software in order to be able to download, but then you just have to click to download, and you’re all set. It really is just that easy. You can even tell it to download multiple URLs at the same time, so you can fill in everything you want to download and tell it to start while you head off to do other things.