Which wifi adapters work best with Manjaro out of the box?

It has known problems. From that github page:

McMCCRU/rtl8188gu: Driver for Linux RTL8188GU (RTL8710B) (VID:PID = 0x0BDA:0xB711)

Known problems

  1. Very slow upload speed.
  2. Problem reconnect from KNetworkManager in Kubuntu 20.04.
  3. In Ubuntu 20.04 detected as GSM modem, need remove option driver as “sudo rmmod option”.

Also, according to @megavolt: