What podcasts/movie/music is good to improve my listening? Most other skills are improving steadily, but my listening is lagging (far) behind. Are there any movies, music or podcasts that can help me with this?
One suggestion is to listen to some old stuff because too many slangs, especially Internet slangs in nowadays movies, TV shows and something else. Even senior native speakers in China cannot understand them.

I used to listen to 成语故事 when I was a kid. I believe you can find tons of them online.