Smart AudioBooks Player is by far the best behaved of the bunch. I think it's partially because it's entirely offline, and partially because it's not trying to sell me anything. It's so much better that I will sometimes extract my audiobooks from other platforms (Audible, Chirp, Libro.fm, etc.), reformat/de-DRM as necessary, and then move them over to SABP to actually listen to them.
Plexamp is probably second best. I find the UI a little confusing, but it mostly just does what I want when I want to listen to my music.
In the past, I used Podcast Addict to listen to a lot of podcasts. It was pretty well behaved also. But I got tired of all the adds and filler in the podcasts themselves and mostly switched over to audiobooks. When I do want to listen to a podcast, I've found that, with sponsorblock, youtube is actually the least annoying option these days But even with that I no longer consistently listen to any podcasts.