The Wizards of Aus was an absolute riot for me! Kudos for bringing that to my attention, I really loved it.
I haven't read many webcomics so I'll probably try some of the suggestions in this thread.
I follow just a few webcomics.
Order of the Stick: Starts as a D&D spoof, becomes a pretty tight fantasy story along the way. Stick figures.
xkcd: So much effort for a stick figure comic, again.
Saturday Morning Breakfast Cereal: Moderately random short nerd jokes. The cousin of xkcd.
Subnormality: Ugliness and far too many words.
Darths and Droids: Unfunny RPG group but somewhat charming.
OGLAF: Increasingly unfunny lechery stuff.
Defunct/finished comics:
Perry Bible Fellowship: Everyone must read it.
Sexy Losers: fap fap fap
don't quote me on this