Longform.org┬ácurates long-form journalism online and shares 3-4 links a day. (They also have apps for mobile devices, if you prefer to read them there.) Not all of them are to my taste, but many of them are fascinating looks at topics I wouldn’t go hunting for.

They also maintain lists (both curated and by tags) – here’s some samples to get you started browsing:

Genre: Online site
Subjects: Varied subjects