When it's really deep and cold I wear Sorel boots.

For snowshoeing, I wear my normal hiking boots with a pair of Neo's over them. http://www.overshoe.com/recreational/ They keep you warm and dry, but you're wearing your normal boots, so the fit is good. When I've tried to wear the Sorels or other heavy boots with the snowshoes, my feet and legs get more tired because they just don't fit like my normal shoes.