There are shirts and there are jackets, but the hybrid garment known as a shirt jacket might be the comfiest fall staple of them all. New York's Saturdays label just debuted its first take on the mule of outerwear, and it features a quilted cotton-blend exterior and an insulated nylon lining. Inspired by vintage outdoor gear, the Forrest jacket is cut like a roomier shirt but snaps on and off with ease and has pockets to spare. Perfect for apple picking, felling a tree, or any other activity for which a streamlined extra layer might come in handy, the jacket offers protection against the elements without the weight of a heavy coat. Also, it gives T-shirts a chance to stay in the lineup as the weather begins to change. [Forrest shirt jacket (shown in Pineneedle); $200;]