Xiaomi Mi 10T with LineageOS 19 (there's no v20 for it) I bought it because I needed a new one that supports 5G and didn't cost a fortune.

Next one might be a Fairphone 5 whenever it comes out. Or a Pixel with GrapheneOS.

I'm also interested in a mobile that runs Linux instead of Android (see PinePhone). But there're none that have good/current hardware.