Why have one pair of eyes when you can have 5?!
I have always been a sucker for the Key frames. The main keys that drive the animation, but I've grown into a complete sucker for the frames you are never really meant to see. Those lovely in-betweens.
I'm working on a really squashy and stretchy piece of animation at the moment and I have just fallen in love with body dynamics and what you can get away with in the in-betweens. We need more CG project's that have a rig you could do these kind of quirky things to...or just more Chuck Jones and Bob Clampett's in the world.
Here is a great little compilation of zany squash and stretch animation:
We need more Cowbell........I mean smear frames!