What's a good life insurance I can get for my parents?

Your parents don't need life insurance at their age. You and your siblings are grown, if both of them are working there is probably term life insurance available thru one or the other employer which will cover the spouse and help pay for old age along with the social security. If neither of them is working then they cannot afford life insurance. they don't need to pay into life insurance so you have an inheritance. sorry.