Well, at some point in time you're going to need the obvious gear but it doesn't always make nice Christmas presents... protractor, ruler, flight computer, headset, VFR flight guide, maps, kneeboard, fuel tester. Very boring, practical stuff and the person giving you the present, in about half of the cases, won't even know what it's used for.
So far, I've had two things that were truly presents. A decent flight bag (lots of pockets, including two that can hold a headset) and a good aviation life jacket (that's the manual inflation type - the one that does NOT inflate automatically in contact with water).
A little less required, but nevertheless useful stuff: Flyer magazine sells these "Driving is for those who can't fly" t-shirts. Or a high-viz jacket, with or without a funny text on it. A good pair of aviator sunglasses. Subscriptions to magazines. Maybe a pilot watch. An introduction lesson on a type you don't normally fly (taildragger!) or a type of mission you don't normally do (unusual attitudes/aerobatics). Or some sort of "free landing+lunch voucher" from someone who wants to fly with you once you've got the license? A maritime survival (aka. "dunker") course.
As for useless but funny stuff, I got myself one of those "I'm a pilote (crossed out) I'm a pailot (crossed out) I fly planes" mugs. The same place also sells coasters, clock and other stuff in an aviation theme. Pins, tie clips with the aircraft type you do fly? "Remove before flight" keycords. Books with aviation cartoons. Plenty of that stuff in typical pilot shops.