Videos you'll have to watch manually
The Shreddit Player fetches the first 3 pages from the "hot" queue (/r/Metal/ front page) or the "new" queue (/r/Metal/new/ submissions) and makes one neat playlist with all the Youtube videos found, so you don't have to click on each and every link. Load the Shreddit Player, lean back, enjoy.
When the playlist ends, it will refresh itself to get new videos from Shreddit. You can also force the playlist refresh with the "HOT" and "NEW" buttons.
Some videos on Youtube forbid embedding into other websites and force you to watch them one by one on Youtube :-( If any such video is added to the playlist, it will be listed below the video player.