And just making the list.. 100 - Richard Wagner's Tristan und Isolde

Some of the most influential music ever written, unfortunately that doesn't make it any more interesting... Beside that the piece is almost unsingable... Let's remember that it is a killer show, two conductors have died while conducting Act 2 and singing Tristan killed its first lead tenor... 

Here is Marilyn Richardson and William Johns for the Australian Opera in 1990.