My MDR V6 might be the perfect headphone. It's the only pair I've tried that are pretty flat and have perfect separation. Shitty mastering can't hide from these cans.

The only problems are the original pleather earcups wear off ($15 replacements are everywhere online), and the cord is pretty long since these are studio headphones. Some people cut the cord by the earpiece and splice a female end, but that's a little beyond my skill set.