Have you ever seen these books by Sandra Boynton? I love them. It's a book and CD pair and they are seriously silly! I use them in almost all of my movement classes with young ones. My favorite are Barnyard dance (animal dance) and Loud and Quiet (see below), it's great to teach opposites with!
My other favorite part about these books is that in the back the songs are written out so you can play them on the piano! My pianist loves (loves!) to play the Dinosaur Round. I teach levels as she plays!
I find the books a reason to be silly, and you all know little kids LOVE to be silly! What silly songs do you use? I would love to hear!