You can use youtube-dl (a wonderful command line utility available eg on home-brew) to easily download the videos at your desired quality and and watch from your HD whenever/however you like.
Some genres are very popular on YouTube but not elsewhere (relatively), New Retro Wave been an example that comes to mind, good programming music.
People often assume that youtube-dl only works with YouTube because of the name, but it actually works with a really huge amount of sites, including Vimeo and Twitch.
You can see the full list of extractors that they have in the source here:
https://github.com/ytdl-org/youtube-dl/tree/master/youtube_d...