Here's another one of my favorite pieces of music: The Pilgrim's Chorus from Wagner's opera Tannhäuser. It starts off pretty quiet, so you might have to turn it up, but be prepared to turn it down as it develops.
I haven't seen the sheet music for the Pilgrim's Chorus, but I have for the Overture to Tannhäuser (at least a piano arrangement of it) which has the same theme and is also incredible; you can listen to it in two parts here and here (another lovely arrangement can be heard here). I was surprised because it was written in 3/4 time, that is, three quarter notes per measure. But each quarter note is divided into triplets, so if he had wanted to account for this in the time signature, Wagner could have written it in 9/8. But that's not even the weirdest part: each triplet is further subdivided into triplets as well. If you wanted to account for this in the time signature, you would have to write it in 27/16. Which is insane.