Call of Juarez: The Cartel on Steam, you'll get a copy of 2009's Call of Juarez: Bound in Blood for free. Just like a few other previous Steam pre-order deals (Portal 2's granted a copy of the first game ), you'll be able to give the game away to someone else if you already happen to have a copy of Bound in Blood of your own.
That's not all: a Steam pre-order will also get you two exclusive in-game weapons, though it's not yet been revealed exactly what those are. Hey -- maybe a chicken cannon. Because, y'know, it's ... a chicken cannon.