[eightails]

I enjoy both Quanta and Aeon. They get linked on HN somewhat often, and for good reason - they manage to balance being detailed and informative on technical subject matter while still being interesting and readable.

The New Yorker and The Economist have already been mentioned but are worth mentioning again.

Le Monde Diplomatique has some great material. Though I'm not quite willing to subscribe, maybe a third of their articles are available for free.