xkcd

This webcomic of "romance, sarcasm, math and language" is written by CNU physics graduate (there's one plus) Randall Monroe, who used to work at NASA's Langley Research Center (another plus!) working on robots (goal!). While frequently NSFW, he's got a lot of great stuff in the above topics (plus a scattering of physics and other science) in relatively simplistic, but effective, artwork (stick-figures, black & white).

If you are using Firefox, be sure to get the Long Titles extension so you can read his mouseover comments without having to do gymnastics with the properties option.

I have many strips that I like, but this one is good: