metafilter is the big one, It's just excellent and well run and actively moderated. I read but rarely post to Reddit. I was at one time an active slashdotter,

metafilter is the big one, It's just excellent and well run and actively moderated. I read but rarely post to Reddit. I was at one time an active slashdotter, and I was active with plastic.com, back when plastic.com was a thing. I occasionally am on StackOverflow, but I think they need to spin off a meta programming question site for half the questions they get rid of as vague or whatever.