Well, this is an easy one. While I admire most of the costumes, I wouldn't actually enjoy wearing most of them. (Though I wouldn't mind stealing pieces of various costumes!) Boromir's outfit may be my favorite, but it's too heavy and confining. And I wouldn't wear a dress unless forced to. The outfit has to be practical, not too hot or cold, comfortable, and allow me full movement for running and walking about. Which really leaves me with Aragorn's Strider outfit.
It's got layers, which is the key to comfortable clothes! Take that jacket off when it gets hot, roll up the sleeves, add a cloak when it gets cold. It is perfect, and I can't think of any other outfit in all the movies I would be as comfortable wearing daily as this one.