This comic is published in the form of a large image. Sometimes it's funny, but more often than not it's some sort of insight about life. Also, the main character is something along the lines of a sphinx. Sometimes. I never understood that, honestly. Maybe it means that she feels like she doesn't belong, but that's for you as the reader to decide. She posts a new comic once or twice a month, and a few of them are sold as posters here. Her comics are a little long, but I always enjoy them. Read her most recent work, and subscribe to the site's RSS feed to catch the next one at http://www.viruscomix.com/subnormality.html
On a less serious note, let's mention Cheer Up, Emo Kid
A very funny panel comic which, according to their site, "is a vulgar satirical webcomic about life, love, and loss." It's been a little while since a new comic was posted, but even their archived stuff is good. Like a few other comics, they post a message when you mouse over the comic, usually pretty clever. Like the name, the comic satires the "Emo" class rather than relating to them, so you won't have to worry about reading about whiney teenagers' hormone-induced false sense of individuality by dressing in exactly what their demi-god Hot Topic says they should (too bitter?). You can find them at http://www.cheerupemokid.net/
Let me plug once more the best, the greatest, and the funniest: Cyanide and Happiness.
They're an extremely funny group of guys with a theme of unfortunate turns of events. They release comics and are starting to release short animations too. A comic is released every day and they also keep all comics archived, perfect for procrastination. Sorry for the next project you've got the won't get finished now. Characters include the Purple-Shirted Eye-Stabber, Seizure Man, Premature-Ejaculation Man, Super Jerk, and the Incredible Sulk. Give them a visit or subscribe to their RSS at http://www.explosm.net/.
I'd like to end on a more serious note with A Softer World
Emily Horne and Joey Comeau's comics are nearly always serious in nature. To be honest, sometimes I feel like they combine random sentence fragments into complete thoughts that somehow have meaning, but usually, they provide some seriously meaningful thoughts. Many a time I've sat in my chair and been able to give some serious thought to something they've posted. Also, their panels are an interesting form of vintage looking photography. If you're in a mood, put on www.rainymood.com in the background and head over to http://www.asofterworld.com/.