If I wanted really useful suggestions from the community I would try to define the application and desired performance of the PCB. I would include things like the environment and numbers of items I intended to see to production.
Those kind of characteristics will help make a more focused selection of which material to use.
A pcb that will be used in a geosynchronous satellite will look very different from one that might be used in a mass produced WiFi router, even if both are operating over the same frequency band. My point is that the question you asked needs to be refined and focused to the particular application before recommendations you receive will be on target.
What is the best tire? Well, which vehicle will it go on? How fast do you want to drive? How much can yo spend? Answer those kinds of questions for yourself and the selection will be much easier.