I would almost say a tablet. Especially if they have the computer in a little back room squirrelled away.
Depends on your folks of course, but my 72 year old Mom who is computer illiterate has taken to the tablet like a duck to water. Dad has had a computer in the house for like 35 years, she never used it. Dad had the tablet I got him for a day and she stole it and he never got it back.