Ok, at first I didn't like this show, because I thought it was too hyperkinetic, but after watching a few episodes, this PBS children's show really grew on me. The show debuted in 2006, and I sporadically watched it, but I find the animation good and the writing fantastic! It's really a very funny and educational show. So far there are over 80 episodes to date.
The basic premise is that Ruff Ruffman recruits a group of kids to do some sort of task like bake a cake at a bakery or herd cattle in Colorado for fun, prizes and points, so in essence the kids are challenged in a "game show" atmosphere that's actually fun, and surprisingly educational.
I'm highly critical of recent PBS kids shows. I feel that "Sesame Street" and "The Electric Company" in their current incarnations are not educational. Same with "Barney and Friends" and "Teletubbies". It's a shame.
"Fetch!" and the previously mentioned on this blog "Between the Lions" counteract this claim and are also fun to watch.