I agree that fleece is a great warmer, but I usually will wear it as a base layer. Cotton sweatshirts are not a good outer layer in rain/snow but neither is fleece.

Basically what I do for my upper body in winter conditions (and everyone has their own methods) is as follows:

thermal shirt (hot chillies or Under $$ Armor) or fleece shirt > hooded zipper Carhartt sweatshirt > shell (I use a Special Blend shell I used to use for snowboarding).

That setup paired with a fleece beanie (skullcap) and a waterproofed boonie hat keeps me pretty darn dry and warm.

being able to drop the shell and still keep warm is why I have found the Carhartt much better than other sweatshirts.

Your mileage may very.


*edit - Fleece shirt http://www.amazon.com/TAIGA-Polartec-Mic...524&sr=1-20