As someone with an avid interest in children's literature--and, by extension, children's entertainment in general--I get excited when I find a true gem, a show that gets it right in every way possible:
It's adorable. It's simple, colorful, playful. Sly. Funny. Gentle. Incredibly original. From the music to the characters' facial expressions and body language...sigh. Masterful. It's never didactic, and it frequently makes me laugh out loud. The web site's nice too (http://www.pocoyo.com/).
Go. Go watch this with your kids, or on your own. It's comforting to see stuff of this quality on the air for the little ones.
Oh, and another great show for guaranteed giggles: Shaun the Sheep. The lettuce-as-soccer-ball episode gets me every time.