...I like the LaCrosse Aero's. They are far and away the most comfortable rubber boots I've owned. I have the 3mil and use a single pair of alpaca socks. When it gets cold, I slip on a pair of Icebreaker overboots.
Just got the lacrosse aerohead 7mm boots. Been happy with them so far. Coldest temp been in the high 20 lower 30.