It depends of the reason and the prognosis for resuscitation. As a veteran registered nurse with a previous specialty in critical care, I have seen and participated in, even led many resuscitation efforts. This question is a good reminder for people to discuss their individual health situation with their physician to help them develop their own advance directives and living will. This really is a very personal decision. Some people want everything done, no matter what the prognosis, and others do not. Most of us do not know what we want until actually faced with a specific situation, and our feelings about our situation can change.
Most people who are dying of a chronic, debilitating illness from which there is little hope for an improvement in health status or life extension should they be resuscitated opt to die naturally without "heroic" measures, but it is important to have given this some forethought and designate a power of attorney for healthcare (POAHC) in the event you cannot speak for yourself. The POAHC should be someone you can rely on to have your best interest in mind and make decisions for you that you would make yourself if you could.
In the most general terms, I would want to be resuscitated to the fullest extent if I faced a life threatening reversible condition with a fair to good prognosis of recovery. That would include intubation, CPR and medication.