Sesame Street: Always a classic, though they're putting out fewer shows these days than they used to, resulting in a lot of reruns. Interestingly, if you buy the DVDs of "classic" episode collections, they include a warning that these shows are intended for adult viewing and "may not be appropriate for today's viewers". Go figure. I guess old episodes aren't politically correct enough.
Clifford: Great books, and a good enough TV show. Focuses on interpersonal dynamics, with the added bonus of a giant red dog. Last few episodes we watched focused on friendship, honesty, and the importance of listening to your conscience.
SuperWhy: Great for beginning readers. They go on adventures to discover new words, characters, and solutions to their reading difficulties. A lot of emphasis on story classics, such as the Three Little Pigs and The Emporer's New Clothes.
A Big World: Not a lot to appeal to adults, I'm afraid, but educational in the aspect of nature and conservation. All the animals sing and dance, which is sometimes painful, but kids love it.
Curious George: If you are like me, you grew up with these books. Focus on problem-solving, as well as simply figuring the world out.
Dragon Tales: Again, not a designed for adults show, but my youngest seems to love it. Revolves around the idea that a magical chant transports kids to a magical land inhabited by dragons and other creatures. A lot of focus on personal/emotional development. I think I would have loved this show as a young child.
Please don't take these as professional reviews, but I thought they might be helpful, particularly if, like me, you are working to find educational ways to pass the summer.