I'd say any Asus router which is supported by the Merlin firmware line.
Code:
https://www.asuswrt-merlin.net
Merlin firmware can be flashed easily over the stock firmware, with no jumping through hoops, and you can always go back to stock easily if you need. They support all sorts of features, including QoS, VPN client and server, and for me at least they have been super stable.
And for 95% of the people, the default settings are perfect.
Considering WifI 6 has been around now for a little while, I'd future proof my purchase by buying one of the cheaper "AX" routers, like the RT-AX56U if budget is a concern. It's cheap, yet a lot newer that the older AC series.
Anyhow, just my opinion.