Music: I love Beethoven's Moonlight Sonata, why is it so great?

Everybody has his own preverences. It depends also on the music you heard in your childhood and how your taste develope over the years. Beethoven is good but there are a lot of other composer.

Here are 100 examples:

https://www.youtube.com/watch?v=gTKsHwqaIr4

this is good, too...

https://www.youtube.com/watch?v=ho9rZjlsyYY

I like Jazz, too:

https://www.youtube.com/watch?v=9vWEa-ydr7A

The chord progressions are clear and logical, and the piece as a whole comes to an end very softly and smoothly.

I'm not a musician but it seems to me that the 2nd movement must be really hard to play, because I can only think of one recording of it that I like.

https://www.youtube.com/watch?v=JFKSdVqIOuQ

Moonlight Sonata wss one of my favorite songs to play on the piano when I was a kid taking piano lessons. What makes it so great is the simple melody, played on a single instrument, with a soothing tempo. I think you would also like The Gymnopedes by Eric Satie. The tempo and melodies are, like Moonlight, somewhat melancholy. You can find the 9 song comosition played on piano and also guitar.