There are events that occur that are pretty important to the characters on-screen, and something like a story arc. Maybe even the remote possibility that one of the characters might even learn something. However, I would never call anything in the series "serious" in the way I think you mean, which is one reason why I enjoyed it despite its obvious flaws.
It's also weird how I felt almost exactly the same way until something snapped around the end of disc 1 (that might have been my sanity) and the series became funny again. Re-watching the eps where I was thinking, "Man, this show is getting repetitive" and laughing at them the second time around is why it really was about me and not about the show. This is what I mean when I said that the show stops being funny because it's repetitive, and then becomes funny again because it's repetitive. However, I can totally get why this would completely annoy the hell out of a lot of people. It's kind of like Monty Python -- some people think it's hilarious, and there are others that just really, really hate it, and you're not going to get either group to move to the other.