The one with fellow traveler.
Traveling, you might have noticed huge difference between short and a long distance trip, and what is interesting, it may have seemed that distance itself is more important, but in real life it is not. Our life obeys only strange and unpredictable rules of chaos, and if in a bus a guy, you are sitting with, is normal, be careful, the next ride, you might be accompanied by drunk man in a business suit or even worse, by a talkative annoying girl, whose problems can be a nightmare for any psychologist.
It seems to me, the greater the distance of a trip, the more important your fellow traveler is. 'Cause being annoyed is not what you want in a nineteen hour flight, hence you are waiting for a reasonable neighbor, who can be a nice interlocutor and who will be accepting to all problems you may encounter during flight.
All this matters only if I speak on my behalf. It's my own experience talking from inside, choosing whom it would have chosen if it had such possibility. But after all we're different, and it doesn't mean that something that applies to me will apply to you. But anyway I guess the best fellow traveler for anybody must be at least clean.