The whole coke vs pepsi thing is weird to me as a buyer for reasons I can't fully explain other than some kind of subconscious deep advertising brain-washing "thing".
For example, sometimes I'm out and about and for whatever reason they don't have my drink of choice, Dr Pepper. So they have coke. I'll drink a coke for the first time in forever and think. that was good.
Next time they'll have pepsi, but not coke. I'll get the pepsi, and think, that was actually really good, I like Pepsi just as much as I like Dr. Pepper. But, when I'm out and about and they have Coke or Pepsi, I always choose the coke, never the pepsi, unless I'm really thinking about it.
So whatever coke has done advertising wise over the last 100 or so years must work really well, because I almost always choose coke, even through my taste buds prefer pepsi.