The eternal debate-- when it comes time to ask which flavors of carbonated beverage a restaurant or friend has on hand, do you ask what kind of pop they have, or do you ask if they have soda? Or perhaps you prefer to call it all coke?
Unsurprisingly, your word preference has a lot to do with your geographical location, as is shown with this map:
Personally, I call it 'pop,' and have been given much grief by a friend in Virginia about it for years. But my Michiganian (sorry, don't like the word Michigander. Makes me think of geese) pride forbids me from calling it anything else.