WFMU is a freeform radio station in Jersey City, New Jersey, I discovered it by accident surfing the radio dial between classes back in 2006, during my first crack at college.
WFMU changed my entire world. In an era where the only radio stations I really knew were KROCK (now defunct) and Z100, it completely flipped my understanding of FM radio on it's head. If I didn't like something, I could come back in an hour and someone else would be on playing something else. DJ's come and go frequently, the schedule gets mixed up twice a year, there's always something fun and new to enjoy.
Even back in 2006 they had a shoutcast set up. I have it configured in Symfonium so that I can listen on my commute, since I don't live in the 91.1 FM transmission area anymore. They were super forward thinking about letting people all over the globe listen. They also have archives of almost all of their shows. Any show you can think of going back to like 2004 probably has an archived episode.
One of the few things they don't archive is Yo La Tengo's Donations for Song Covers, which they do every year as a part of the marathon. These became the sources their albums "Yo La Tengo is Murdering the Classics" and "Murder in the Second Degree" Gotta tune in live for that one.
The other thing is they are completely listener-funded. NPR gets government grants (as small as they may be), WFMU doesn't. I make sure to donate every year. The Marathon is a two week period in February & March every year (I believe they start March 3rd this year) where they try and raise money to keep the station going for another year. I'm glad I get to live in a world where this exists, and even if you don't have the means to donate, it's a really fun time to tune in.