For many people it seems Reddit's the post-Digg destination. Certainly Reddit has been growing by leaps and bounds and trying to keep up.
I stopped visiting the main reddit page a few years ago and stuck to proggit since then, but that also seems to have suffered a lot recently.
Does anyone know if the ex-proggit folks just moved somewhere else?
Then there are lots of specific communities you can sign up for depending on your religious beliefs that have various values... /r/emacs /r/vim /r/haskell etc. most of the language specific subreddits have decent traffic.