(2) More humane ways to die. Given a choice, would you rather die peacefully in your bed, or any bed, really, with an injection or jump in front of a moving train? I thought so. I rest my case.
(3) Die in more responsible ways -- paper works can be drawn up to take care of the person's property. Heck, there will be businesses set up to help people arrange all matters after death. Really? Would you rather your neighbor go in a responsible manner, or until you smell a foul smell and call the police to crack open their doors? And if the person is healthy and a suitable donor, organ harvesting teams can be arranged. The person who CHOSE to die can go knowing that their death will allow MANY others with STRONG wishes to live live. It's a good deed... and a bargaining chip with God should their decision be met with disapproval at the other end.
(4) If we are truly so intelligent and, especially in our country, the awesome US of A, we value free will so much, why should we be allowed to choose when to create a life, but not when to say, "Okay, I have live enough, I think I can/should move on now"?