I don't like RDR because I just don't like western setting period, but that being said RDR is by far the better "game". Meaning LA Noire is almost like a point and click adventure then a fully actioned game. It was a good first try for doing what they did, but it needed more action and diversity. The story wasn't that great especially the ending, and something happens that leads you to a different desk that I personally didn't like, it contradicts the story and main character as a whole. Isn't explained well why and just made me stop enjoying the game.
For me when a story presents itself as being the #1 thing, and LA Noire does that because that is pretty much all it has is story, I try to align myself as best as I can with a character based on the fundamentals of its belief system. LA Noire flat out contradicts that late in the game and never explains it.
RDR is a game 1st and story 2nd. The gameplay is fun and there is alot of action to get into making it more of a game period.