What is the most challenging music to play on a stereo?

A now deceased friend who was very wealthy built a gorgeous home and began setting up a very fine system with MacIntosh pushing the power. I don't  remember all the peripherals but it certainly was big bucks all the way. He was never happy and asked me over for some advice. OMG, it was horrible!

People who live in glass houses should never seek great sound. The entire front of his living room was thick plate glass 12 feet high and probably 40 feet across. The music he enjoyed got lost chasing each other around the entire room. Much against his partners  chagrin I told him to have heavy drapes installed that he could close when he wanted to sit and listen. He did what I said and they both hated it but he invited me back after the installation. You can't have your cake and eat it! They wanted to have the view while listening. When he drew the drapes, probably about a $20K install, his system came to life and became fully satisfying to both of them and me. The moral is, before you go spending gobs of money fixing your system, spend some time and effort fixing your room. Very possibly you will find it Fugly but it sure could sound way better.

Late-era Autechre.

That’s easy….Bad recordings. 

You should play the music YOU LIKE!!  

I don't care one whit how opera sounds, because I hate opera!!  Some of the best sounding new music made today is country, but I hate country music too!  I love 80's synth pop and rock, so my system better make that sound real good.

And then there's always Steely Dan!!  

Agree on classical. However, if you actually attend a concert, it’s not really that loud. Depends on the piece, but blasting some crescendos isn’t going to tell you much. I’d go for organ. It’s actually the first hi-fi rig. It’s listening to how it reproduces ranges of textures, tones,  transitions from midrange to bass. And the same recording on two different organs should be radically different because of reproducing the space. 

Also, play something groovy. If you move, tap toes, etc. that’s the point. If you hear a band live that just isn’t getting you to move something is holding it back. Amplification probably is a bigger source for this but lack of decent bass too. Or some call it PRAT. Things out of time are easy to tell. They just don’t swing.