Yes, the stop motion in Clash of the Titans is quite humorous at times. As an aside, though, I wouldn't call it unwatchable since I watch movies for the stories rather than the effects, and its story was entertaining enough, although I have to admit I was pulled out enough to laugh at times. But that doesn't mean that all stop motion is better than CG. The stop motion in Empire Strikes Back, for example, coupled with the painted backgrounds, is still more convincing to me than any of the CG in the prequels. It never for a second pulls me out.