My absolute favorite genre falls under the inadequate term of "post-rock." Some of my favorite bands include Godspeed You! Black Emperor, A Silver Mt. Zion, Sigur Rós, Tortoise and Mogwai. I started listening to this kind of music about ten years ago as I transitioned away from indie, alternative and classical as my favorite genres. It was around the same time that I became interested in vintage audio, namely Acoustic Research speakers, which really could bring out the incredible characteristics of the music I was listening to.
Godspeed and ASMZ frequently use elements of classical music and composition in their recordings, which, in my opinion, pairs very nicely with older gear. When I am trying out any piece of equipment, my audition album is usually F#A#∞ on vinyl. Unfortunately, I have not found any contemporary gear that can adequately playback these bands with the same effect as the vintage stuff. Then again, I probably can't afford any contemporary gear that can playback this type of music to my tastes, but I digress.
I am also very interested in rare and obscure jazz, hard bop, and fusion recordings. I am a big fan of Madlib and admire his ability to dig up some of the most pleasant and obscure music I've ever heard. Thankfully, Madlib periodically puts out compilations of the music that inspires him so I may take up the task of finding the full albums of the songs he samples in his music.