I've played Ninja Gaiden Sigma for the PS3. Dope game, all-around.

Well, maybe except for the camera sometimes.
I own Black. It's one of my favorites actually. I've played through all the levels on Black Ops, beat it 100%. [best level is Spetriniv Gulag] The game is actually pure ownage. Using the grenades and RPGs make it kinda easy in sticky situations though, if be one. The only bad things I never liked about it was there's only 7 or so levels, and you don't really unlock anything interesting.
Good news though. If you like Black, you'll be glad to here they're coming up with a sequel of it sometime this year, TBA, for the PS3 and 360. Cheerio.