Nobody did even mention Focal until now. Neither do I. Don`t like their sound and chichi-appearance.
Probably because most of the comments are from 2010, and at that time Focal wasn't making any headphones?
Anyway, I guess I'll be the first to mention them in my list.
1 - Focal: They're built in France. They are beautiful to look at and they feel incredible. They have made a lot of well-respected headphones, some even consider their TOTLs to be the best dynamic headphones in the world currently. Their service in the EU at least is excellent, offering 5 year warranties and such. Obviously they have flaws, like a lot of companies, but the fact that they only made their first Hi-Fi headphones in 2016/2017 and yet managed to make a name for themselves says a lot. (Obviously their past helped, but that wasn't a guaranteed win.) I'm also a huge fan of their house sound, and that's why I only bought them up to now.
2 - ZMF: I haven't had the luck of listening to one of their headphones yet, but I truly respect them a lot. Their headphones look incredible, they offer a metric-ton of choices, there's also a lot of craftsmanship involved, they're really active in the community and that's the kind of company I would like to support. I'm a huge fan of the R-10's design, even if a bit bulky, and ZMF is basically the modern equivalent in design. As for sound quality, I've heard a lot of extremely positive things, and some consider the VC to be the best closed-back dynamic headphone in the world, even better than the Stellia. (I personally think it comes down to taste, as always with anything over 1k.)
3 - Sony: I really appreciate Sony as a brand, they've been making headphones for quite a while, all of them with some really interesting and quirky designs, and while I know they're not to everyone's tastes, those who do love them truly do. They liked to try. I'd love to listen to the Z1R and their previous hi-fi headphones.
4 - Stax: They do have quite the aura as a headphones company. I was able to see a few of them IRL and I really enjoyed their design. If you don't know what they are, they look really goofy for sure though. Their TOTLs are also contenders for the best headphones in the world, I don't have to add anything more. I'd love to get my hands on one.
5 - Meze: They've been gaining traction for the past few years, and I always respect newcomers making a name for themselves. I personally don't think I'd enjoy their warmer sound, but again you don't know until you've tried. Their build quality is apparently out of this world too, and their flagship is supposedly incredibly comfortable.
6 - Sennheiser: I had to add them, obviously. One of the most well-known headphones company, their HD6** is legendary, and I also consider the HD800(s) to be a legend too. Like Stax, I'd love to get my hands on the HD800(s).
7 - Hifiman: Their lineup is well-loved, and they apparently sound incredible. They're also the makers of the Susvara, one of the best headphones in the world. They also have a lot of options at different price points, which is a huge plus.
There's a lot of different brand out here, but those are the most interesting ones for me. This list is completely subjective (I've only heard Focals and never wanted to look back after all) and not only based on sound quality (That's the priority, but comfort and look/feel is also really important to me and I'd gladly take the second best option in sound if it's comfy and well-built).
Bias aside + taking flaws into account, I'd say Sennheiser takes the top spot (Safe choice, but most of their lineup is forgettable or huge flops, like the HD700 and the HD820, and while they're unbreakable, they're still made of plastic), then Stax (Let's be honest, the materials kind of suck + really expensive), ZMF (Hard to get one, really expensive, and you need to love their sound signature), Focal (Questionnable design choices like the Elear/Elex voice coil, the infamous clipping, the discoloration and the creaky headband. crappy service in the US + really expensive), Hifiman (Has quite the reputation for QC, the build quality isn't the best, even the materials chosen are meh. They also have a tendency to stealth upgrade), Meze (Sound signature is apparently meh for the price), Sony (Same as Meze, they also don't seem to care much nowadays).