Not a fan of God of War, but DMC3 and Black roXX!
DMC3 has a better combo system than Black, but Black has better graphics, more adventuring, and A.I focused fights.
Offense = DMC3 wins
Defense = Ninja Gaiden wins
I love 2D gaming, and that's what DMC3 is really, 2D twitch based gameplay in a 3D world. ROCK ON!
DMC3:Special Edition, I'd get that. It has ultimate fuckin pussy mode, and infinite continues, and what RE4 does with Ada in the PS2 version, DMC3 does with Vergil on the Special Edition version. And there is a mission mode/bloody palace challenge thingy with a theater mode.
It'll likely be the Greatest Hit version of DMC3, as it's still priced at 49.99.
...btw, I don't think God of War wins in any department, cept for graphics. I liked Ninja Gaiden's platforming/puzzles more (aside from the lousy camera sometimes)
God of War's puzzles felt like genre breakers, Ninja Gaiden's puzzles flowed well with the action.
DMC3 really doesn't have puzzles...just insane action and insane cutscenes.