Can anyone recommend some android alternatives?

I'm not looking to move away from android permanently but I'm just curious, I enjoyed my time with UBports (fuck QT) and seeing projects like the PinePhone and Librem 3 just get me curious what is actually out there.

Currently rocking a pixel 2 XL but not shy on buying new hardware to test stuff out as long as it's within reason.

Currently had a look at PureOS (not available) and Sailfish, any others to give a whirl?