Gift ideas for parents and grandparents?

The only irreplaceable thing is Time, so the gift of your time would be priceless. You could give them "coupons" for your time doing some chore that needs doing, company to play a game or watch a favorite movie/TV show, etc. It could be chores like: cleaning the bathroom, cleaning the curtains, weeding [if they have a yard], cleaning out the attic/basement/garage for an afternoon [they may need to be there to make decisions on what to toss, keep, donate, etc], or company for Sunday dinner, playing Uno, etc. All of these will be MUCH more personal than a "thing" and show them that YOU feel they are important. Also, none of your hard-earned money is used.