KEF Space One (the original, wired version)
KEF M400
KEF M200
NAD Viso HP50
Koss Pro4S
Denon AH-D1000
Sennheiser HD 58X Jubilee shipping today or tomorrow, I think.
I've never heard Sennheiser headphones before, so I really don't know what to expect from those lol.
I love my KEF headphones, they sound very much like KEF speakers (I own plenty and have heard many more through the years haha).
The NAD HP50s do have a similar kind of "speaker sound," but they don't do explosive dynamics very well compared to the KEF models I own, bass is muddier and not as extended, and there is an odd coloration that shows itself most on some female voices (Kathleen Battle and a few other sopranos do not sound like themselves!), so I think they are overrated. Or perhaps they don't have good quality control, and I got a bad set, since so many seem to rave about them. Most people don't listen to the music I do, so it could be that the worst flaws don't show up in their listening like they do with mine.
KEF Space One is my favorite of my headphones. I got them for $99 from NewEgg on Black Friday. Every genre of music sounds fantastic on them, although 99% of my listening is classical music, with the other 1% being Mariah Carey, Chris Isaak, Ella Fitzgerald, Sarah Vaughan, and Patti Page. I have tested Heart, Led Zeppelin, Jimi Hendrix, Cream, Blue Öyster Cult, Metallica, and some other hard rock and heavy metal, and they all sound fine, so I'd classify these headphones as great all-rounders. They are over-ear headphones, but they're a bit on the small side, so that may be an issue for some. The pads press a little on the bottom of my earlobes, but it's not uncomfortable for me. Switching between using these or my KEF LS50s at my desk isn't jarring, so if you own and enjoy the LS50, you might check these headphones out. NewEgg still has periodic $99 sales on them. These are the wired version, NOT the newer wireless model. I never use the noise cancelling feature. Isolation is fine without it, in my opinion.
The KEF M400 on-ear sounds wonderful, but I don't recommend them to others as there is a common issue with the wiring for the left driver, I got mine for $79 a couple of years ago on Black Friday.
The KEF M200 in-ears sound fantastic, but I discovered that I really loathe having anything sealed in my ears, so I haven't used them since my initial test. Fortunately, I won them, so I wasn't out any money haha!
I bought the Koss to have something sturdy that I could take out of the house if I wished, their sound is more than adequate for their purpose.
The Denons are older than dirt (15 years old, maybe more?), I bought them thinking I might need them for nighttime listening in an apartment years ago, but the neighbors were all loud and rude, so I never worried too much about being quiet, so the headphones didn't get much use.
My headphone amp is the JDS Labs Atom, and I've been extremely happy with it.
Edited to add: my Sennheiser HD58X Jubillees arrived about an hour ago. Testing with favorite operatic sopranos first: Leontyne Price, Anna Moffo, and Kathleen Battle so far, and all sound like themselves haha! So that's a relief. JDS Labs Atom on high gain, at 1:00 position (with the KEF Space Ones, I use the Atom on low gain, at 2:00 for classical). First impression is that the KEFs are more detailed with singers slightly more forward on the 'stage.' Bass is tighter and more extended on the KEFs, and there is some muddiness/congestion in complex orchestral music with the Sennheisers, but it's not too bad. The massed forces (orchestra, brass band, real artillery, choir) on my favorite recording of Tchaikovsky's 1812 overwhelm the Sennheisers a bit comparted to the KEFs. The KEF Space Ones were only $99, but had a list price of around $400, so I think these Sennheisers are wonderful at $150 including shipping. Other than sound leakage, there isn't a huge difference in the general sound between these open-back headphones and the closed KEFs. So far I like them very much! Trying Honey by Mariah Carey now for something totally different haha!