Chess Game Commentaries
Agadmator
Agadmator has a huge collection of 10- to 30-minute entertaining commentaries on games by great players.
Chess Network
Jerry briefly explains key strategic ideas, and why some ideas would not work, in a selection of famous games.
John Bartholomew
30- to 60-minute studies on key issues such as passed or backward pawns, dealing with unexpected captures, etc. by an IM (International Master).
Mato Jelic
Aimed at younger or newer players, Mato pauses at a critical point in each game to let you see if you can spot the key move. A good collection of short, instructive videos.