I think one of my husband's favorite gifts I've given him was a picture frame that I put a few pictures of us in with little comments and decorations - sort of like a scrapbook page. It was just something that he could put anywhere he wanted that could remind him of our time together - and we both like that. Plus I think hand-made gifts just have a warmer quality to them sometimes :)
the two best presents that I've given my bf (according to him) was a stainless steel flask by waterford, and a licensed dc comics shirt with the flash on it. Both were things that he had really been wanting, even though he usually prefers to get practical gifts.
Happy anniversary! I've been thinking about the exact same thing. My boyfriend and I's 4 years is March 5th! I want to make him something...Idk. Last year I made him a really rich chocolate cake in the shape of a heart, I got him flowers (weird, I know!) and painted hearts on them, and I bought card stock and painted the front, and put things that reminded me of us (Hobby Lobby or other craft stores sell tons of stickers and little things like that) inside along with a note.
Does he like beer? Or BBQ? They have beer and BBQ of the month types of things. That's manly!
Ok, if you're against that then how about doing something extreme (non x-rated) with him to celebrate your anniversary? Something like skydiving or bungee jumping! It's definitely a shared experience neither one of you will surely forget.