KEXP
It's a little odd tuning into "the morning show" in the afternoon, but it's good radio, and so much better for discovering music than any of the alternatives here.
6 Music can be as good, but it never quite got over the "death" of the UK indie music scene and sometimes feels more like a tribute act to it's former self. As I speak the heaviest tracks in rotation are from Bon Iver and Doves, and while both are great acts, they're not new bands. Overall the discoverability is way down, and fairly often I'll find new music, even music from UK+Ireland, via KEXP, rather than from the media here.
Each is not always good 24x7 but when they are good they are so much better than any playlist I've ever heard. You're just not going to get a Firebunker(RIP) or Cousin Mary or Alma de Barrio without the humans.
WTMD, Colorado Sound, WEQX, Koto.fm, Mountain Chill, WETA, WMRW, 102 Cue, KCRW all get a lot of play around here.
Radio feels dead because most places have been taken over by a couple major broadcasters. Radio is awesome when people care about it, is still a fantastic institution of lots of small local shops doing amazing things for great good.