Anything that supports the latest version:

https://openwrt.org/toh/start

Its very hard to recommend a specific product, because manufacturers keep coming out with new, low-spec versions of their own flagship devices under the same model number. Can be very frustrating to find you've bought the XXXX YY.ZZ (7) variant that has half the RAM of the (1) through (6) but costs 20% more.

Now I just go with whatever is available second-hand.

It depends what you want, if only router and speed is not a problem one of those tplink, if you want a 4g/5g modem inside gl.inet. if you want with modem also a Fritz box.

Devices with #OpenWrt as a stock firmware

https://openwrt.org/docs/guide-user/installation/openwrt-as-stock-firmware