If some alien offers me this deal, I would rather not make a deal at all. I will fight and they have to kill me. But I will die knowing that I was free.

There is some chance that I will accept the deal, just to buy more time and find weaknesses in the aliens. Anyway, I would prefer to die free on my own, and I would prefer that my family gets to take my body and cremate it, or give it to earthly elements.