Best sounding headphones you have owned?

Stax Lambda SR (non-pro) here, I have been using them for about 30(!) years and although I have tried many others, nothing comes close for overall SQ.  I like the Utopias, especially for bass, but anything acoustic on the Stax is just amazing.

I've had a lot of TOTL headphones come through here, including Abyss, ZMF, Focal, Meze, Audeze, and others that are slipping my mind, but the winner for me is Susvara through my Eddie Current amp.  I do use Utopias with my DAP though...

I own and use STAX 009s and Audeze LCD-XC headphones. I recommend both highly. Two of my favorite phones from the early years are STAX Lambda Signatures and Yamaha YHD-1. The Yamahas were made of some cheap plastic and broke easily, but they did sound much better than their modest cost would indicate. I recently sold my vintage Lambdas, along with a tube STAX driver unit. I hated to see them go, but...

RAAL SR-1b with TI-1b interface, without a doubt.  No other headphone gives as true a representation of a live musical event in a performing space, period.  So what if they don't have massive bass, perhaps their only drawback, although the bass they do produce sounds much more realistic than closed compression bass found in earcups.  Many other phones are good but the SR-1b moves the needle forward like no other.  IMO.

@rlawry You are correct! Listen to the SR1b with the new RAAL Star8 cable (I also have SR728) and the VM-1a tube amp. A Lumin X1 is great as a DAC to this but I still like the Benchmark DAC3B into the VM-1a. That Star8 cable is some genius work. All silver and works so well with what I consider bright gear.

Only thing is, make sure you have payment ready to go. No joke.