This topic from Long and Short Reviews reflects something that used to be an issue for me, but no longer is.
My husband, you see, is hell to shop for because when he sees something he wants, he buys it. He's also very good at finding gifts hidden around the house even when he's not trying to, so I've given up attempting to surprise him and I just ask him what he wants instead. Believe me, it's easier. My usual fallbacks of gift cards, wine and mugs aren't going to work on him.
However, I did manage a good one once.
On one occasion a friend asked me in exasperation "What do you get for the man who has everything?" and I jokingly replied "A box to put it in." This turned out to be a great idea. My husband collects watches, and while I can't afford the sort of watches he likes, I could easily afford a leatherbound watch box for him to keep them in. And he loved it - so much that now he has several.
I'm keen to know what everyone is going to suggest!