For many years, I've made enough money that the the things I want are either easily affordable (rock climbing equipment, a gaming console, etc.) or completely unrealistic as gifts (two round trip first class tickets to Taiwan). And this is compounded by the fact that I'm the most expert person among my friends and family on most of my interests.
So for many years I've asked people not to buy me gifts for birthdays or other occasions, but to instead donate to an animal advocacy nonprofit (and I'll suggest some to them). I'm _much_ happier to see them spend some of their money improving the state of the world, as opposed to getting me stuff that I don't need or could purchase for myself any time I wanted it.
That said, some relatives still get me gifts, but at least they're very usable, like gift cards to my favorite restaurants or book store.