National Geographic Kids: goofy but great
This one actually comes from one of my favourite web design sites, A List Apart, which suggested National Geographic Kids as an example of a site that "focuses on clarity (…) even if the site is also goofy" [>> article].
Now it may seem a bit goofy if you're an adult but if you happen to be a kid "goofy" probably isn't your reaction when you read "Ruins, Romans and the world's best pizza". And the videos, games, activities (etc., etc.)… why, they look like fun, which is maybe how learning should look!
Sure, I'm a kid: yeah, maybe I am a bit goofy but I also know what kind of website I like!