As much as The Economist is good, it's still news, which has negative effects on the mind + it's too focused on global economy which don't really have any value for me, maybe to an actual economist/global leader, it would

XXX Review of Books are good, but they're basically convoluted essays. Good for anybody else, not for my time though

Aeon focuses much on philosophy. I no longer read this though because it's too academic for my taste

Brain Pickings, Arts & Daily, 3 Quarks Daily focuses much on classics, mostly - I'd rather read classics that reading writings about classics, nowadays