Brands are subjective. They don't really matter as they can all make both good or bad boards. You need to look at each board soecifically.
If you're looking at x399 boards for a 2950X, any of the high end options for X399 are good choices. So it really depends about the other addons you're looking for. Don't pick by brans.
Top 3 most popular boards/best reviews are the:
- Asus ROG Zenith Extreme
- Asrock X399 Taichi
- Gigabyte X399 Aorus Extreme
All of these boards are top options. What you need now is to pick what "options" you need/want. Like how many pice slots you need, M.2 slots, number of fan jacks, looks, design, usb ports, supported ram speeds, RGB or not, etc... etc..
Check out this link for differences:
https://www.techinformed.net/best-x399-threadripper-motherboards/