I searched around a lot with this same question and I have put about 100 miles on Conti GP 4Season 700x25 the past ten days. I was concerned about tire clearance since I have a standard road frame, not a cross bike, and I've had two sets of Vittorias that ran large but also one set that was true to rated size. You won't have that problem with 28mm so either tire is good.

They're both pretty expensive. They're both well-rated in the rain and overall rolling resistance. But the GP4S has a much better reputation for flat protection and longer life.

Oh and since I'm riding in the winter too, I installed Mr Tuffy Ultra Lite liners. Maybe it's an unreasonable expectation, but I'm hoping to have zero flats. You get cold pretty fast changing a tube at 30 degrees.