It's one of those things that it depends on where you're from as to if it's soda, pop, soda/sodie pop, cola, or a softdrink. To me, it's either a cola (as they are Pepsi Cola, Coca-Cola, Royal Crown Cola) or softdrink (as opposed to hard drinks with alcohol), with soda and pop only applying to the hand-made concoctions at drug stores and ice cream/soda shops, that mix soda water with flavored syrup or ice creams.
As for me, my favorite softdrink/cola is Dr Pepper.
Here in Texas, the generic for a carbonated beverage is sometimes just "Coke". So, you can have a conversation that goes like this:
Person A : You want anything?
Person 2: Gimme a Coke.
Person A: What kind?
Person 2: Dr Pepper.