Well, the title pretty much says it all. Unemployed again, so I've got lots of time on my hands and little to do with it, so webcomics are a pleasant interruption in an otherways dreary day.

So far, I like:

Order of the Stick
Least I Could Do
Girl Genious
Goblins
Flipside
Sinfest (semi-NFSW. Nothing too graphic, but language)
Questionable Content
UserFriendly (semi-RIP )

I also sporadically read about a dozen others (including XKCD, Looking For Group, PVPOnline and Between Failures). Any other suggestions of webcomics are welcome (although I generally prefer well-drawn webcomics).

EDIT: Added linkage. Oh, and webcomics with a long history would be excellent.

Rice Boy / Order of Tales ~ Two for the price of one
Dresden Codak ~ Great art, sometimes too esoteric for me, but otherwise awesome
Copper ~ Features a talking dog

Darths and Droids (What would happen if Star Wars had been someone's DnD campaign)
Oh My Gods! (unfortunately, after 2100 strips, the creator has decided to step away from it, meaning there will be no more. Sad day )

I have a big ol' list right about here that I am not going to type again. But it has many comics on it!

Absolutely take a look at Digger.

I'm sure Phoebus would agree with me that the best webcomic out there is Sweet Bro and Hella Jeff.

Sweet Bro and Hella Jeff (And the real comic they are attached to can likely be found too)
How about a ninja who is also a doctor?
8 bit theatre just ended, but Warbot in Accounting and How I killed your master are pretty good
SMBC- hover over the red button for an extra panel, sometimes. Also, the videos are pretty entertaining
Amazing Super Powers, the secret panel is in top righthand corner on all of them
I am not sure why I stopped reading this. Oh right, the little sanity I had left.

My favourite is so nsfw.

Does it start with an O?

Yes.

Gunnerkrigg Court

The Phoenix Requiem

Dreamless - This one is almost finished and is not terribly long.

Afterstrife Finished

Wonder what this is...?
haven't really kept up to date with this, but it's good stuff.

QC and Qwantz, pretty much.

This man speaks truth.

And just to add some that haven't already been said (considering I read most of everything already mentioned... oi)

Buck Godot
Starslip
Afterlife Blues (and their finished project A Miracle of Science)
City of Reality
Housepets!
Almost Pets
Oh-no, It's a Dinosaur

Hopefully a nice smattering of randomness

Nobody ever seems to mention Achewood. It's got some insane wordplay and the author's hella good at creating unique voices for each of his characters, but it can be disturbing at times. Most times, in fact. The current arc's a pretty good example. Always be sure to check out the alt text, too.

Apart from that, all I've got's the usual: Dinosaur Comics, Dr McNinja and the inestimable Erfworld.

Achewood's in my list I linked to I picked up a lot of silly speech habits from Achewood, namely the occasional "hella", and using the word "all" too much.

Also, Nice Pete is so freakin' terrifying.

Oh I know what you're thinkin' Pat

Is he gonna kill me too

The answer is I don't know

Killin' is a special thing

It's a special thing you do
when you want someone to die