Final answer:
The philosophy best suited to help terminally ill client and their spouse cope with unfulfilled desires is to live each day to the fullest, as it aligns with the hospice care goal of comfort and dignity.
Step-by-step explanation:
The hospice nurse caring for a terminally ill client should utilize the philosophy of living each day to the fullest to help them cope with their concerns about 'never doing everything we wanted to do.' Hospice care is geared towards providing death with dignity and focuses on comfort over cure, allowing patients to pass in peace, preferably in the comfort of their homes. By encouraging the patient and spouse to live each day to the fullest, the nurse supports a positive outlook and making the most of the present moments, which has been associated with increased satisfaction and better coping for both patients and families receiving hospice services.