HD 600
In light of the recent uncertainty of Sennheiser's Consumer Division, I recently picked up the HD 600 after a few years of putting it off and being content with my HD 58X and DT 770 Pro (250). I wouldn't consider myself to be a true, enthusiast-level audiophile (or whatever you want to call it), as I don't think my ears are nearly fine-tuned enough to pick up some of the subtle differences often described, but I'm more interested than the casual listener, so maybe somewhere in the middle? In any case, these have been on my radar for quite some time, as they seem to match the overall sound signature philosophy of what I was looking for at a reasonable price point. Not necessarily an end-game pursuit, but hopefully a good reference point to add to my modest collection.
I did my best to check my expectations at the door, since I figured there was a non-zero chance that they'd be closer to the 58X than I anticipated, given my current critical listening abilities. I was pleasantly surprised by how wrong I was! From the first listen, these have done nothing but impress. The ease with wich they pull apart your music feels almost surgical without being sterile. Compared to my Beyers, they obviously feel more transparent due to being open-back, but in a much different way than the 58X. Transparent, clear, and precise. I've seen a few descriptions of feeling like you forget the headphones are there because nothing is overtly emphasized, but it's crystal clear, so they just kind of "fall away." I'd say that's perfectly accurate. They are most noticed by how many things you don't notice, if that makes any sense.
These are definitely my new favorites and absolutely live up to the hype, but in a very understated way.