Well I've done all kinds of stuff...So far this year I have socks, candy, and men's body wash (I found some that is shampoo and soap all in one and that is right up his alley!). I'll probably pick up some mini bottles of liquor too. Those are always kinda fun.
I've also done gift cards, which I know is kinda goofy since we share an account and he can spend our money how he chooses, but I sort of angle it like use this to go out to lunch or grab a coffee on your way to work type stuff. I've also done books or a small calendar. Other things I've done-- a spatula (he's the pancake maker in the family), a flashlight, a headlamp thingy, tools and other weird stuff that makes M. giggle.