Okay I've given it a search, and it appears, bafflingly, that no-one's started such a thread before. So, after long deliberation with fellow Crackpots, I hereby found this thread in the name of..erm...Comicdom?
I'll start with some off the top of my head, naturally:
DISCLAIMER: I do not want to act like you are internet newbies, but I still have no perception of how many people like XKCD for example, so excuse any unintended patronisation.
Hyperbole and a Half
http://hyperboleandahalf.blogspot.com/
The author's name is Allie Brosh. She has made me giggle uncontrollably once in the past through her humour. I particularly recommend the 'ALOT' comic, though you can find the 'best bits' down the side anyway. I'd recommend skipping the latest comic until you get to know her, because the latest one is quite devoid of humour (but very enlightening about depression).
XKCD
www.xkcd.com
Many of these comics go over my head - as Randall Munroe discusses everything from advanced mathematics to candid love (and I shure don' unnerstan' that) - but it's the great expression of character, wit, and above all intelligence that gets me in these very simple (but always effective) comics. Also, check out the 'What If?' section. It's a gem.
Dinosaur Comics
http://www.qwantz.com/index.php
Everyone loves dinosaurs. Everyone loves philosophy. Some people like template-based comics. Put them all together and you have something some people will love!
Perry Bible Fellowship
http://pbfcomics.com/
For all the lovers of slightly darker humour. This comic doesn't update regularly at all, but there's a good backlog and the artwork is fantastic. I implore you check it out.
Okay, so now you post your favourites, and let us discuss like good internet tribespeople.