If you were able to pick one person other than yourself to live forever, with no questions of personal attachment, i.e. this was a one-time thing and everyone understood that you were making the choice for the benefit of some greater good, who would you choose to live forever? Why? Assuming that immortality would grant them indefinitely extended life without any of the usual complications of senility, feebleness, weakened immune system, etc. without the requirement of consuming human blood or whatnot.

I could see people choosing a spiritual leader, or a great thinker of some sort, or in medieval times, a great leader in a time where terms of reign aren't limited... Some people might choose loved ones, but if it's a one-time choice, it might be a curse as well; whomever was to become immortal would have to face that they were going to outlive their loved ones.

It might make for an interesting world, if the ticket to becoming immortal was to be so well known and respected and loved that one would be the obvious choice by the randomly or deifically chosen dispenser of immortality. Being a villain? Sucks to be doomed to mortality! Unless the dispenser of immortality likes villains, of course.