What are the best-built popular high end furniture brands?  

Maybe
it's time to get a magic 8 ball?

Give me Fritz Hansen
or give me death.
Or give me a haiku on the subject, if you can't give me either of the above. I'm really not that picky.

Mainstays
You know where

American solid-hardwood
makers that come to mind: Room & Board, for the lower end, in walnut, etc, and Thomas Moser (production quality par excellence), originally limited to cherry an d ash . . .

..... ....... .....
Room & Board, Kabab?
Magic 8 ball, grasshopper
Let it speak to you.
Aunt Mark
ps evil in the womb.

"High End"
Practically speaking, I consider "high end" to simply mean Fine Furniture, the kind of thing that is not disposable, but not necessarily only for movie star and aristocrat incomes etc.
If you buy from Internet Lifestyle Catalog type companies you are buying all of their associated marketing and convenience policies too, this will not ultimately reflect a good comparative value... these companies are importers with healthy profit margins.
Some good American solid wood furniture-
Thos. Moser (as mentioned above) can indeed take one's breath away, this is pretty expensive, can be 2k for a dining side chair
Harden furniture has some similar pieces, lesser priced
Also Copeland, and Lyndon still nice but simpler and cheaper
There are Amish companies such as Abner Henry that do very good work as well, "craftsman" style for the upper end of the interior decorating market (middle class, anyway), these sources will be like Stickley but with greater customization.
All of these things can potentially work with mid-century modern styles but are often more influenced by American Colonial styles, Shaker in particular.
In my experience, though, middle class consumers will often pay premium prices for what could be described as junk (relatively) because the pictures are so pretty and you can just click and her friend did it and it got so many facebook likes etc.
Perceptions of quality vary very widely by demographic, and most people don't know how to see.

people here try very hard to help you
HouseKebab
Your thread, "best-built popular high end furniture brands", indicates ignorance of the field and your reply, "______ mass market tres gauche design wanna-be poser brand (that is significantly more expensive than Target and Walmart) is the best built", is resentful.
I am sure that Riki, Mark and others on this forum, regardless of their beginnings, do not look negatively upon those with less or more. HouseKebab, people here try very hard to help you.