I've owned and used a number of winter/expedition tents. My big monster is an old Moss Little Dipper (it weighs as much as my complete 3-season pack these days, but good for a bunch of people and canoe trips). An old favorite is a WPB Garuda Kaja. But my new favorite is the Fury. The Fury is about as "bombproof" of a winter tent as you'll find, but relatively light. I don't have the gall to actually lay on top of the tent, but the frame seems rigid enough to do it without harm... if someone has a Fury they'd like to offer up to science let me know.
Somewhat anecodotally, I've had the first two tents I mentioned in 60+MPH winds and in snowfall of nearly 2 feet overnight. The Fury is at least as strong and capable as the other two, perhaps more so than the Kaja. But the Fury's relatively new to me, didn't get a chance to use it in any horrid conditions this winter.
EDIT: Sometimes I make assumptions, guess I shouldn't... :P For more info on the MSR Fury, do a search for the Moss Stardome. MSR bought Moss tents and the Fury is a remodel of the (remodeled) Stardomes. A very well-proven design, beloved by many.