I love some of the 2nd Viennese stuff, like Webern's op.6 for orchestra. It's almost like musical pointillism,
Another way to enjoy the 2nd Viennese School is to listen to their transcriptions of Bach, Brahms, Mahler, etc.
I love John Adams as well, and the textures he writes for his orchestration is really phenomenal, and a big challenge for any audio system to reproduce. They all live in the upper midrange and treble with lots of struck percussion, and heard live, they form a kind of atmospheric texture that I haven't really heard reproduced well over any system.
I think Webern was actually a tremendous romantic, and instead of "points" of music, Webern is creating a total absence of ornamentation, and wants us to focus on hearing an extended and very romantic, expressive musical line. Actually the idea of Weberns music as pointillistic comes from a French/English theorists Mis-translation of the German word "punkt" which was used by a German critic to mean "punctuated" or without ornamentation, rather than pointillist.
Weberns Op. 21 and 22 are great examples of this.
The Schoenberg orchestrations of Brahms pieces are absolutely sublimely beautiful, and well worth hearing. These guys were hugely capable and well educated composers and theorists in the late romantic tradition. Might check out Britten's "The Poison Tree" or Milton Babbit. I personally Love Messiaen as well.
Having played a lot of minimalist music, the percussive and syncopated piano writing in that genre is incredible. It makes the piano ring like a bell across its entire range. You stop hearing fundamentals and just hear overtones and ringing string notes rubbing against each other. It's one of my favorite parts about piano, and learning for example Hallelujah Junction, China Gares and Phrygian gates really took my relationship with piano to a level that even technical music like Liszt, Chopin, and Rachmaninov could not. You truly love the sound of instruments when you experience that kind of "writing for overtones." It's phenomenally difficult to record those sounds (speaking from personal experiences attempting to capture them while recording myself and others, and playing for others) systems with extreme purity of sound are required, as are extremely good mics and a nice room. Still hard to capture that beautiful pulsing sound.
You might like Darcy James Argue, or Maria Schneider who are doing some very cool things with minimalism fused with big band and folk music. Eight Blackbirds new album Hand Eye is very minimalist-leaning, I think a lot of contemporary composers are turning to a new kind of accessibility while not compromising complexity. Very cool.
Glad to see a fellow contemporary classical appreciators on headfi : )