I'm subscribed to Matt Levine's Money Stuff[0] about finance, computers are bad[1] about retrotechnology, and A Collection of Unmitigated Pedantry[2] about history. The common theme through all of these is their focus on big picture systems, which I enjoy. I'm also subscribed to the Orbital Index[3] which is about space, and is more focused on small scale current events than the others.