I just started season 3, and I'm getting a bit tired of the "Monster of the Week" episodes, that don't further the main story arcs. With several more seasons to go, I'm ready to start skipping episodes to get caught up.
What are the episodes I should watch if I only want to follow the main story arcs?
I'm okay with skipping episodes that provide background for sub-arcs, if they don't provide background for primary arcs.