I'll start with a few I've found over the years (and one yesterday lol)
Nectarine Demoscene Radio
A classic. They have a gigantic trove of demoscene music (not just chiptune). ~44,000 songs and growing. Streams have historically been a bit spotty depending on where you tune in.
Bitfellas BitJam
More demoscene radio, but heavier on chiptune coverage.
NightRide.fm - Chillsynth
Started listening to this yesterday, and so far I really dig it. Seems like it has just the right amount of energy and rhythm to keep me going, but not so much as to ruin my focus while I'm coding.
Feel free to add whatever you love.