At the time of death what is the ideal mantra to chant, or image to have? The scriptures say that if you do it right, you can achieve moksha (liberation). Also, what can the family members chant or whisper or do for the dying person to help liberate them?
Om Namah Shivaya is what I would say.
Om Namah Shivaya or Om Namo Narayanaya or Hari Om; any of these.