I think it will be Paul, he's a little younger (but that might not make a big difference), and he's a vegetarian. He takes good care of himself (not that Ringo doesn't), and going veggie keeps out a lot of health problems. I'm a vegetarian, I know all about it.
I hate to even think about this happening! It will be the first time I experience it, since I wasn't born when John died and wasn't a Beatle fan till long after George did. All I know is that I'm gonna ball my eyes out when it happens to them. OK, I should stop talking about this, it's making me depressed! They have a long way to go, though. I think they will both live to about 90. That cheers me up!