I'd go with the worst enemy. I mean, my best friend is awesome, but I'd rather have one person's life on my hands, not 7 billion minus one.
Death is merely a transition through which I would free my best friend from the earthly chains which bind his tortured soul and enable to soar into eternity where he can look down upon those left behind and say there, but for the grace of God, goes I.
I would choose neither! No matter what happens I'll find a way to save EVERYONE!!!! I hate those bitter-sweet endings. I will never give up until I find a way to win! Why!? Because that's what heroes do!
****...that's messed up. I choose myself...the world can live without me.
My enemy hates me. My best friend loves me.
If I choose my enemy, one person dies and a great person.
If I choose my best friend, then everyone dies, not a good thing in my book.
I don't have an answer.