I myself only played Ninja Gaiden once or twice, but I beat God of War. Overall, I like God of War better, primarily becuase of the character and the simple, yet satisfying storyline. The interactive-cinematic fights between bosses, and certain enemies were very sweet, and were done in such a way that it didn't take away from gameplay. Ninjai Gaiden was awesome becuase it of the fighting system. Probably one of the deepest systems to date, and it was extremely hard. Plus, you play as a ninja, that alone makes the game cool. Overall, It's really a matter of opinion. I think both games have up's and down's and it really just depends on which one you like better.