No contest, save the person I love from a horrid death. One, I love them, why the frack wouldn't I? Two, how the hell could anyone say they loved someone if they were willing to let them die a horrid death?
Though, if I also loved this other person of whom I could go to the moon with... I would at least weigh the options, consider if this person I love, kind of had a painful death waiting for them on account of how they lived. Judgmental, sure, but you know the sort and I'm a sucker for broken-souls as it were.
You went to a party, someone slipped you something that made you black out. Next thing you know you're falling from 100 floors or more up. Do you try and flip over to face the sky or do you watch the ground get closer?