https://rg3.github.io/youtube-dl is the tool I use for this.
You can download a single video or an entire playlist.
You can also use Firefox + http://www.downloadhelper.net extension.
The Downloadhelper extension also allows scraping HTS streams, by playing them + recording the stream + dumping the stream into a file.
Here are 2 wonderful resources, that I recommend and use all the time, for free use videos that you can edit. Not all of them will be what you are looking for but you should be able to find some that work well!