Depending on which Ninja Gaiden, as that came out in the 1980's, but the same level of GOW as in "3rd Person Action Adventure, 3D", then Ninja Gaiden (2004)...
BUT, if you go back to 2001...
Devil May Cry, in my opinion... Ever played it?
Made by Capcom in Japan.
GOW crosses over quiet heavily with whole hack and slash, collecting Orbs, big environments, battling enemies and bosses, Save Points.
But with a different type of theme.
DMC is built on fantasy creatures while GOW is Roman Warrior / Spartan / Greek Mythology orientated.
But in both games, everything is exaggerated, which makes it fun and wicked!
After completing Resident Evil 2, Devil May Cry, was suppose to be next Resident Evil (Resident Evil 3: Nemesis) but the style of DMC was different from RE, as it was a Survival Horror game.
It did not go ahead as RE but instead of abandoning the project, it became another game and a good addition to the company as it was a very successful series.