Sealskinz primaloft winter gloves are reasonable quality, but not quite as warm as they look, and rather expensive. I've used mine for thousands of commuting miles, and after about four years they are now very tatty and ready for a new pair. Be careful with sizing, as they can come up quite small, even in the larger sizes, and tightness will restrict circulation, making your hands colder.
I also have a Sealskinz skull cap for underneath my helmet, and that is great. Definitely recommend, as even if you get hot and take it off, it requires almost no space at all in a pocket.