Discover Weekly is great. The only downside is that when Spotify magically generates a new playlist for you each week, it replaces your old Discover Weekly playlist. Now, thanks to IFTTT, there's a super easy way to keep an archive of your favourite ephemeral playlists.
You will have to give the applet permission to access your Spotify account, but once you've done that, it's literally as easy as clicking a button to turn the applet on. Now you will have a playlist that keeps an archive of your Discover Weekly playlist. Pretty cool!