I have loved every God of War.
I played them in the order of release, so the relative lack of polish in the original God of War wasn't really an issue, and I could forgive Chains of Olympus for being crap slightly shallow because of the hardware limitations of the PSP.
When I first played God of War II, I loved it like I have loved very, very few games before. It stands as one of my all-time favourites. And if I'm being honest, in retrospect, God of War III didn't quite topple it for me. Yes, it is brilliant. Yes, it deserves every bit of the 9.4 I gave it. But I just don't feel that it has the same quirky and original charm as GoWII.
God of War II > God of War III >>>> God of War >>>>>>> Chains of Olympus (not to say that CoO is bad, of course. It's still GoW)