I think email newsletters are undervalued. Here are some of my favorites:
- Money Stuff by Matt Levine
Truly a stupendous amount of good content about, well, money stuff. Publishes every weekday. (A recent favorite.)
- Gwern by Gwern
Stuff Gwern has been reading in genetics, machine learning, social science, and statistics. Publishes once a month. Amazing & intimidating.
- Benedict Evans by Benedict Evans
Silicon Valley trends by an a16z partner. Always high quality. Publishes once a week.
- Axios China by Bill Bishop
Stories about China, usually on the economy & US-China foreign policy. Publishes once a week. I don't know enough about China to follow many of the stories, but I appreciate the overview. Bishop also writes Sinocism, a daily newsletter also on China.
- Five Links by Auren Hoffman
Five things the CEO of SafeGraph enjoyed reading. Publishes about once a month.
- Robin Sloan by Robin Sloan
Interesting miscellany by the author of Mr. Penumbra's 24-Hour Bookstore, often about design & new fiction. Publishes every few months.
- Future Perfect by Vox
Vox's Effective Altruism vertical in newsletter form. Publishes weekly. I don't read most of the content, but it's interesting to follow what happens to EA as it passes through the Vox filter.
- Adventures in Typography by Robin Rendle
On typography, publishing, and graphic design. Publishes occasionally.
Also I've heard the Daily Stoic is good, but I'm not subscribed as I prefer my mysticism-infused self-help with an Eastern tinge.