I Do Not Want to End Up Incapacitated and Diagnosed via Videotape by a Member of Congress.

Good. Me neither.
http://www.washingtonpost.com/wp-dyn/articles/A48119-2005Mar18.html

If you don't want anyone but you, your doctors, and your loved ones making decisions about whether you'll live or die, you need an Advance Health Care Directive, otherwise known as a Living Will.

In the event of your incapacity, or vegetative state, or coma, or something like that in which you can't express your wishes, you can instruct certain people to do certain things.

You can provide that only a certain person make decisions about the care that you get or don't get. Here, you want to designate one person and then designate one more person as backup in case your first choice is dead, also incapacitated (same car accident?), or otherwise unavailable.

Or, you can provide that you would like certain procedures, like a feeding tube, or that you do not want other procedures, like a respirator.

Some states require that these documents contain specific language, so there's no confusion. These states thus provide forms that are worded in the way that the state statutes require.

Thus, it is not advised that you simply pull a form off the internet and cross your fingers. Find a form used by your state so there's no extra anguish and expense of using a court to decide. End-of-life decisions are grueling and costly enough as it is.