Eeeerrr... Hell send them bitcoin to their wallet address and leave a note under the tree that says "check your wallet".
You didn't read the article. It's on the list!
What do you give to the one friend who exchanges everything that you get them? Some cryptocurrency, of course!
I also think this is the best gift, much better than a hardware wallet. What would you do if you were a no-coiner and got a hardware wallet? Most people would sell it online to people who have crypto but if you got cryptocurrency and saw it grow in value you might think about buying a hardware wallet yourself or ask for it next christmas.