Well, if there is one - and only one - way you can "choose" to die (if we rule out any forms of suicide, of course), but one that is determined by chance and happenstance, I really have only one vote to cast:
I'd opt for the CERN particle accelerator in Switzerland to malfunction, in the process creating a black hole that would consume the entire planet (and then some). I mean, anyone can die in a freak accident or be struck with a disease - but damn, how's dying in the f***** end of the world for you? EPIC WIN... FAIL... SOMETHING?!
On a more serious note (as end of the world seems a little drastic, if it's only one person's death we're initially talking about), I think I would like to opt for the more heroic way, too. Saving a number of people at the expense of my life, if there is no other chance... I think I could live... erm... die with that.