The best are still vacuum dielectric or air dielectric. They’ve been around forever, but they come in small values at high cost. I use these exclusively in my phono / pre.
Film and foil are next best; styrene is pretty neutral, teflon a bit bright, polypropylene a bit dull. Some examples are ’very’ rather than ’a bit’.
Metallized are constructed by depositing metal onto the dielectric. Quality appears to depend on the thickness of the metal and the junction of the metal to the wire leads. They can be almost as good as film and foil, or almost as bad as electrolytic. Mica and teflon are the best.
Ceramics tend to be inferior to metallized, the quality seeming to depend on the dielectric constant of the ceramic, lower being better.
I don’t have strong opinions on paper in oil, but I really don’t like leaks, so I avoid them.
Good luck! YMMV
Film and foil are next best; styrene is pretty neutral, teflon a bit bright, polypropylene a bit dull. Some examples are ’very’ rather than ’a bit’.
Metallized are constructed by depositing metal onto the dielectric. Quality appears to depend on the thickness of the metal and the junction of the metal to the wire leads. They can be almost as good as film and foil, or almost as bad as electrolytic. Mica and teflon are the best.
Ceramics tend to be inferior to metallized, the quality seeming to depend on the dielectric constant of the ceramic, lower being better.
I don’t have strong opinions on paper in oil, but I really don’t like leaks, so I avoid them.
Good luck! YMMV