Yeah, I'll have to go with the Red Ring with this one. In comparison, Rorschach doesn't so much have a "lack of fear"; I'd have to say he's got better "rage" than almost every other character I would know of in the DC-verse, save for, maybe, Doomsday or that "Embodiment of Pure Rage" being. He would probably be best for Red in any case; I don't see him as being so much noble as he is psychotically-inclined.
Green Lanterns are for... well, the goody-two-shoes of the Universe, pretty much, in general. Also, I despise Parallax. Useful side note.