I've long thought that anger is an integral part of good humor. I'm not talking about Sam Kinison on stage here, screaming about operation desert storm. Good humor draws attention to the ridiculousness of our behavior, and lets us acknowledge it (semi-) safely, but you're not very likely to do that without a healthy amount of outrage, and a good clean eye on the dirty ways of the world.
Could anyone honestly tell me that they think Matt Groening had a positive childhood? And yet, the ridiculous and abusive behavior of what was no doubt Groening's own father gets tweaked probably only slightly, and suddenly, you've got Homer Simpson, who's hilarious. Life with Louie (a much better show than it was ever given credit for) was just Louie Anderson riffing on the fact that he had a shitty childhood for 22 minutes at a time, kind of like “A Christmas Story”, the animated series.
The best examples are all about processing difficult childhood issues, but it certainly doesn't stop there. Even Robert McKee has a joke in Story about a Christmas party with only comedy writers being one of the most unpleasant experiences possible.
And yet, I'd like to talk about “Family Guy”. I was never a huge fan of it, though I certainly don't object, and I find nothing wrong with the format of “I'm going to riff on pop culture references in rapid succession for an entire episode”. Nevertheless, I find the show interesting, because it so perfectly captures the Adult Swim style (despite originally starting on Fox). Personally, like with Family Guy, I'm not a huge Adult Swim fan. I'll watch a lot of their stuff if it's on, but the only show that I've ever intentionally sought out was The Venture Brothers. Really, Adult Swim is just on the very front of this new wave of humor, largely based on nihilism. I can't think of anything that typifies this better than the youTube poop phenomenon. (Has it surprised anyone else that it's yet to receive its own Wikipedia article, but is mentioned by name in the Wikipedia article on CD-is?)
If you're not familiar with what I'm talking about, look at the following: http://upload.wikimedia.org/wikipedia/en/3/3e/BowserSourpussToast.PNG
If you're like me, you find that picture really funny, but can't, at first glance, explain why. The short answer for why it's funny, of course, is that it's ridiculous. It features characters you're familiar with (Mario, Bowser), doing unfamiliar things (holding bread, sponsoring bread). This isn't like some dumb picture of a political figure where somebody photoshopped a bong into their hand, that's funny (well, not really, but you get the idea) because it's somebody intentionally flipping the meaning of the photo. Someone who normally stands for not using illicit drugs becomes an icon. It's a subtle jab at the hypocrisy of whoever is in the photo (politicians, cops, church leaders, whatever), which wouldn't be funny or relevant if we didn't have a vague sense of outrage at the hypocrisy of authority figures.
Mario holding Bowser brand Sourpuss Bread is definitely not that. It's funny because it's completely nonsensical. Why would Bowser make bread? Likewise, when Peter gets into a fight with a giant chicken, the joke there is that it makes no sense.
I submit that this is the inevitable consequence of the rising tide of relativism. People are realizing that standards they were brought up with aren't necessarily universal, and on the edge of that is people experiencing a backlash, and toying around with the concept that without absolutes, there exists the possibility that nothing really matters, and everything is as good as everything else. Humor that is designed around things not making any sense brings us face to face with that fact, and lets us deal with it safely, in the same way that The Simpsons does for alcoholic abusive fathers in dysfunctional families.