Nobody ever takes me seriously when I say this but here goes: the very best adult Christmas presents are....fuzzy slippers and cheap perfume for a woman and a wallet or a tie for a man, even if he has no money and never wears anything but tee-shirts. I'm not kidding, these really are good presents! Presents are meant to be symbolic. If you stress out over finding just the right present for every friend and family member you'll never enjoy the holiday.
If you're like most people and you think what I wrote above is crazy or irrelevant then here's my fall-back suggestion: give the person something completely unrelated to what they're interested in. It has to be something good mind you, something that's the best in it's field, but something the person has never even thought about. I don't smoke and I'm not really interested in cigars but I have to admit that I'd be curious to smoke what people in the know consider the best cigar. Maybe smoking isn't really a filthy habit at all if you smoke the right stuff.
On another subject, Chrismas shopping is sooooo stressful. I still don't know what to get my wife! Every year she always says, "I don't see why you're having so much trouble getting me a present! There's only two things I don't want: don't get me anything useful like an appliance because everybody benefits from that and it's not personnal. And don't get me something that's not useful because the house is filled with stuff like that already. Absolutely anything else would be fine!" And every year I always answer with gritted teeth, "What are you talking about!!!???! Every single thing in the universe is either useful or not useful! There IS nothing else!" This is an irreconcilable conflict.