Radio Paradise delivers the good - FLAC quality streaming with no commercials. I generally don't stream any "radio" sources for "critical listening", more for background music, but the sound quality of Radio Paradise certainly holds up for "critical listening".
I listen to a nice FM tuner (Magnum Dynalabs etude) all day while working, to a good quality NPR jazz station. Sound quality is also excellent, but most of the time it is background music.
There are a number of lists of CD quality internet radio stations. This looks like a good one - CD Quality Internet Radio - High Resolution Audio (hiresaudio.online)