While this map,
Generic Names of Soft Drinks by County, is a few years old (how can 2003 have ended three years ago - can someone explain this to me?), I'm happy to report it's accurate at least for my home county, where the author reports 80-100% call it a "coke" (although Matthew of the East Central U. Dept. of Cartography and Geo. should have checked his spelling. Just saying).
So, poll -
A: If you're either from the U.S. or living here, is the map accurate for your home county?
B: What do you call it?