Hmm, very interesting.
If we're talking non-diet cola beverages I'd have to go with Safeway Select Cola. Between the two, Coca-Cola and Pepsi, I like Coca-Cola if it comes from a can and Pepsi if it comes from a bottle. Call me weird, but this is my life.
Now for the diet beverages. I like Diet Pepsi a hell-of-a lot more than Diet Coke, doesn't matter - bottle or can. I don't like generic diet drinks of any kind.
My favorite soda is Sprite. I don't drink much soda these days but if I do, it's usually a Diet Pepsi.