My kids pretty much only watch PBS shows on TV. On the upside, they're decent shows, and at least mildly educational, and they don't make my kids act TOO crazy.
The downside, of course, is the liberal propaganda, and again it's pretty mild. Mostly recycling and other enviro-bs like that, which probably most kids shows have (hell, NBC has turned their prime time line-up over to the Greens). So I try to balance that by saying, "you know, this stuff really isn't true."
Anyway, this morning they were watching "Martha Speaks," which is a pretty good show. The episode was about an alternative-energy cart race---the kids in the show were building carts run by solar, wind, etc. I thought, "oh Lord here we go," but what was funny was at the start of the race the solar car rolled 5 feet, then stopped because the sun went behind a cloud. The wind car just sat there because there was no wind. I thought that was pretty funny.
Of course, the wind car won eventually because basically a gale blew up, but still.