I have the first Call of Juarez and when it came out, I thought it was very unique and have kept it. And I had CoJ: BiB and thought it should have been co-op but I didn't keep it long.
As for RDR, it's an amazing game in story and graphics. BUT...they lost me when they added zombies to it and I passed on that DLC. Still the main game ISPs worth the cost.
Gun...never played it. Never wanted to.