Schofield Revolver in general is just my favorite. I had mine have a blackened steel and nickel body and a pearl grip with a buck engraving (an eagle engraving on the off-hand revolver), making it the direct invert of Micah's Revolver.
Although it’s a pistol, I love the M1899. I just got into Chapter 4 and I bought it and it’s awesome. The best thing I like about it is that it has a magazine so you don’t have big reload times.
LeMat, it's very useful with it's many bullets and shotgun ability. However i'm more of a pistol guy, and in the story i've got a M1899 and in online i use a Mauser, but my offhand in both is a LeMat for ammo reasons.
LeMat revolver. In terms of actual gameplay, I do prefer the volcanic pistol though. But in terms of the revolver, but the mat beats out every other one with its capacity, damage, and versatility.