Long sleeve, a vest and a shell.
Over the years I have accumulated some amazing vests that I use depending on how cold is it, my favorite are the: Arc'teryx Atom LT, Patagonia Nanopuff, Marmot Variant, Mammut Broad Peak and Mammut Aenergy. And then if needed, I just put a gore-tex pro shell on top.
I have riden through bad NYC winters this way and I find it to be the perfect form of top layering.