Oooh, difficult, kind of thing that keeps me awake at night.
I value my life nearly above all else, seeing as I'm an atheist, and so don't believe we go anywhere when we die, but I also value the life of others, and would never let someone die without trying to save them first.
This is the kind of situation my ability to think logically works quite nicely. Other people might get destracted under stress, but my 'I don't give a crap' attitude lets me analyze much more throughly.
Now, if there were NO CHANCE of saving us all unless I killed myself, then that'd be a problem.
...
But I guess that 6 lives, or even one life of an element of Harmony, values more than mine.