Spotify because I’ve been on it since it was in beta, so my music recommendations are really good. I just don’t really feel like starting over.
I’m also grandfathered in with a deal where I get Hulu with it (Hulu has commercials but whatever, I don’t pay for it), so I don’t really feel like giving that up.
I use Downcast. I can’t give you an argument for that over any other apps because other than the Apple podcast app, this is all I’ve used. It works great.