 If you liked
Noir
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 ...then you might like
Darker than Black: Kuro no Keiyakusha
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Both are very psychological, have well-choreographed fight scenes and influences from film noir. Homewer, Noir setting doesn't involve sci-fi or fantasy elements.
Both involve assassin's trying to figure out a mystery in their past and fighting other assassins. Contractors technically aren't always assassins but act like it a lot. Hei and Noir are both such skilled assassins they are compared to grim reapers. In both the antagonist is a larger organizations, the Syndicate and the Soldats, which seem to manipulate everything behind the scenes.
The strength of both are definitely the great fight choreography and soundtracks. Weaknesses in both could be considered the plot and characters. But if that didn't bother you one it hopefully won't in the other.