You, statistically, have a gamer in your life. If you do, you, overwhelmingly likely, will have to buy some Christmas presents for him or her this year. Maybe, though, you don't know anything about games.
Solution No. 1: just absolutely lose it and buy the first thing you can find from a garage sale and you think maybe it's some kind of sham hand-held Nintendo product that never left Japan but whatever it's, like, December 22 and you're out of ideas. Or, Solution No. 2: stick to smaller stuff you know they'll like because, chances are, if they wanted it they'd already have it.