Completely agree with simonmoon. But...there’s nothing wrong with dramatic spatial effects produced by studio tricks in rock music. In previous threads on this site, people have commented on how, with a good jazz recording, the drums are often centered and in the rear, as is typically the case live. So, besides "classical," acoustic jazz is another good source of "natural" soundstage. But having said that, I have no objection to drums spanning the entire width of the room, with a snare on the far left, say, kick drum in the center, high hat and tom on the right. On Tool albums, for example. Not "realistic," but exciting, engaging.
As for "dark, thorny, atonal" contemporary "classical" (and that term strictly means Haydn through mid-period Beethoven; neither Bach nor Mahler are "classical" composers): give Arvo Pärt a try. There’s a terrific recital CD on DGG with Grimaud and Salonen, called "Credo" that includes Beethoven’s "Tempest" sonata, his under-appreciated "Choral Fantasia," and Pärt’s title piece. That last is an amazing trip: from a sublime quotation of Bach, through the most anarchic fff cacophony, and right back to Bach. IMO, a musical evocation of the difference between Old and New Testament ethics (although Pärt evidently had a critique of tyrannical government in mind). The SACD is the best Big Orchestra recording I’ve ever heard.
Pärt’s "Te Deum," on ECM, is another favorite. From his "Tintinabuli" period, it sounds medieval, but is scored for chorus and digitally-amplified aeolian harp and prepared piano! I’ve listened to this gorgeous piece at least once a week for most of the last year. It’s also beautifully, spaciously recorded.