My husband have had the same annual fight every year for going on 24 years now. It regards the correct manner in which to apply tinsel to the Christmas tree. Personally I hate tinsel - it makes a mess, the cat eats it and walks around dragging out of his ass, etc. But my hub insists on tinsel for a real tree (no artificial tress here - not even from Michaels).
So as I am already somewhat resentful at having to use the stuff in the first place, this sets us up for a disagreement about how much, where, and how it should be added to the tree. I prefer sparse, thin strands, judiciously applied, and careful not to obscure the ornaments. He just goes with GOBS. FISTFULS. BUNCHES.
It was, in the early years, a knock-down drag-out fight. Now we're too old and tired. So we don't argue about it anymore - he does half of the tree his way, gritting his teeth over what I'm doing on my side. And I do my half my way, gritting my teeth over what he's doing on his side. And then I wait for him to go to bed and I remove some of his gobs. And he gets up earlier than me the next morning and adds some bunches to my delicate strands. And we never say a word about it. And this is how you put tinsel on your tree and make a marriage last for decades.