I figure there probably isn't an appetite for a lot of opera threads, but I'm starting this one because this week on PBS in the U.S. they are playing the full Der Ring des Nibelungen. All four operas, after the introductory program tonight. It's a new and though somewhat tricky with the moving set, stunning performance.

Great Performances Wagner episodes

Anna Russell's take on the Ring Cycle

Wikipedia summary of the operas and librettos

SRS