Just finished God of War: Ghost of Sparta. Its only the second time ive played it and damn im impressed. I honestly think its the best of the series alongside GOW II.
The story is much, much better than GOW III and it sets up the second game brilliantly with Zeus fearing him and Kratos furious with the gods (I was worried how they would make the story work set between I and II but they pulled it off spectacularly). After the events of Chains of Olympus, GOW and then Ghost of Sparta it helps you root for Kratos more in the later two games because you sympathize with him better. Its hard to route for him in GOW III and even in GOW II at times because he seems such an angry dick, but after playing both the PSP games alongside the main games you get to see why he has so much disdain for the gods.
It may only be on a small PSP screen but its probably the most epic of the 5 games in my opinion. And its got some of the best bosses of the series. I love how the Scylla monster appears as a boss intermittently throughout the first hour and then during the finale showdown with it, it brings down Atlantis. Thanatos' daughter is a brilliant boss fight as well and I loved
Spoiler
the creature his mother turned into after revealing the secret
.
Now onto GOW II.