@gregkh sure not the "best", but I recently went for an "ASRock X570S PG Riptide", this mainly so I didn't have to pay for a new CPU and loads of DDR5 and pay twice as much for a motherboard, but from what I did notice was that x670 boards seems to be better than x870 boards, if you are going with the latest generation of AMD CPUs.
@gregkh anything branded ASUS Strix is a safe bet usually. I tend to favor mainstream models when bying motherboard, usually they get longer support than niche models
@gregkh Have been using ASRock motherboards for AMD Ryzen processors and they haven't disappointed me (yet).
@gregkh I've been looking into the same, a Zen5 workstation motherboard, the last couple of days. Take away is that if you need a PCIe slot for more than one >=4 lane card (in my case, a 10 GigE NIC + a cheap graphics card), the x870 series of AMD disappoint by forcing the mainboard manufacturers into strange lane assignments. Most boards really have one x16 "GPU slot", some m.2, and the rest is electrically x1, which is useless.
Seems the sensible way is Zen5 9950X+ an AMD 560 mainboard.
@gregkh ... unless you want more than four DIMMs of RAM, then you'd need to directly go for an Epyc and a server board. Which costs you >1000€ more for the same 16c/32t performance. But Zen3 Epycs are getting cheaper, so if you don't want current generation, that might be an option.
@gregkh let me know if you find one that doesn't suck, all PC mobo firmware stuff seems major amateur hour. Like why yes I would like to manually download this random binary from your support site to update my root of trust that has a bunch of typos in the UI. Mmmm yes those ACPI warnings in my boot logs certainly don't worry me.
@gregkh asus mobos suck, I've problems with both Lan and wifi :) Lan dies every 1h, wifi randomly dies and you should shutdown pc from the line and spam turn on button to discharge capacitors (maybe it's mediatek fault).
Just buy something like QCNCM865