As was said before, you pretty much nailed it. I was going to start this very same thread two days ago (when I finished GoW3 for the second time), but there's really no competition.
1 was the only one with a cogent story and somewhat-deep and well-constructed characters, whereas 2 eliminated any emotion/thought involved (Me Kratos, me angry, rawr) and introduced time-travel. Time travel. I could go on and explain all the reasons why this is bat-shit retarded and makes no effing sense whatsoever, but you already know. 3 did try to make the best of the total garbage that was 2, and for what it's worth, I think they did a pretty decent job considering.