In my humblesse opine, this is the greatest comic ever to exist since the caves of Lascaux were first marked by some mega-jaw-man.
XCKD (a webcomic of romance, sarcasm, math, and language) has lots of great comics. I don't always understand them when they are based on maths and science. It's often kind of nerdy. As am I. I can go there and hit the random button for hours, or 18 minutes, whichever comes first.