This question is the very reason Oleg started this new forum to take the place of the Round Table! To hash out important philosophical questions such as these.
I grew up in S. Mich, calling it "pop". Then, after spending a career in Air Force, took to calling it "Soda".
Now, living here in the swamps of Coldwter, I still call it "soda", but find myself reverting back to "pop" on occasion.
I voted "soda", because that's what I call it most times.