I'm voting for the Field Bag, #3. I think it's classic, stylish and if you need it for books or to hold some folders then it will work. I also like the duffle but it's too small to fit the books or folders.
I have the classic field bag and i bought it for school and work- i love the everything about it- but you have some fantastic choices so i do not think you can go wrong-
Now I just need to trek down to a Coach boutique that carries both the classics and the men's line, which is a difficult combination to find.