I remember, I think I was watching Deadwood or something and just thought to myself how amazing the landscape and scenery was in old west movies like Magnificent Seven, then thinking about how great an open-world game set in the Wild West could be.
You could travel from town to town, helping out Sheriffs and Outlaws, ride trains, hunt animals, fight or help out 'Injuns' etc. At the time Call of Juarez was coming out, but I didn't think that FPS was the way to go to best make an old west game, considering the limited weapons and how little exploring is done in linear shooters.
Then I heard about Red Dead Redemption, and it seemed like everything I was hoping for.
tl;dr: Game looks awesome bro.