Coding

fgiesen.wordpress.com -- The ryg blog - for it's deep insights into hardware.

c0de517e.blogspot.de -- C0DE517E - for the rants that keep my bias tilted.

www.iquilezles.org -- Iñigo Quílez (IQ) site about raymarching, ShaderToy and more. The most informative scene-coder site since cubic.org.

nothings.org -- Sean Barrets homepage - with stb_image.c and similar zero-bullshit libraries.

So called facts

www.cgpgrey.com -- Interesting 10 minute videos in fact-overload-style

subbable.com/crashcourse -- Astonishingly deep videos, considering the state of the world.

Fun

www.xkcd.com -- If you don't know this I can't help you

www.smbc-comics.com -- A daily comic strip that is hard to describe...