I had tried to listen to Wagner before, Tristan und Isolde, specifically, and I wasn't impressed. But after doing my homework, I discovered a couple of things. One, you really need to get a good recording to appreciate it. I had bought a bargain bin copy of that opera, so I missed the mark there. Two, you need to listen to it at very high volume. Once again, I missed that the first go-around. So I did even more homework, and found the Daniel Barenboim-directed version of the entire cycle and turned the volume way, way up.
In a word, it's sublime.
I actually started listening to the cycle last winter. Each one of these operas is several hours long, a huge commitment of listening time, so I made sure I had a good day to listen to each of them when I was sure I wouldn't be interrupted more than a bare minimum. Unfortunately, by the time I got through with the third (Siegfried), it was spring. And it just wouldn't do to listen to it without a cold, howling wind outside. Just yesterday I finally finished the cycle.
Of course I know nothing of opera, but as a metalhead I was able to appreciate every minute of this nearly 15-hour masterpiece. I don't know German or the conventions of opera, but I understand bombast and drama, magnificently dynamic shifts in volume, tempo, and tone. The leitmotifs in the composition are also enough, in themselves, to give me a hook to the narrative thrust of the thing. In case you didn't know, the leitmotifs are melodies that are attached to specific characters or things in the story, which has laid the foundation for modern soundtrack composition. You'll hear it in the soundtrack to the films in The Lord of the Rings franchise, for example, or if you want to hear an irritatingly graceless version of it you can watch the children's show Dinosaur Train.
The bottom line, for me, is I can't speak highly enough of how enjoyable this was for me. It gave me an enjoyment something like listening to--in various degrees and for different reasons--great funeral doom, or Iron Maiden, or Therion at their best, but distinctly different from any of those.
Obviously I can't recommend this to everyone. If you enjoy funeral doom, you'll have the patience for the huge time investment. As for the monetary investment when you're not even sure you'll like it, you might be able to find a copy at a library. As to whether you can't enjoy the art because Wagner might have been a terrible person, well I can't help you there.
But if you're on board, then let's build an opera house, revel in the majesty of these works, and then burn the fucker to the ground.
(This video gives just the merest taste.)