I used to hate skiing because whenever I fell in the snow (which was quite often), snow would get up my back and down my pants making me wet and miserable.
All that's in the past now, and I love rolling around in the snow because now I have a bib. A bib is essentially like over-alls, so they go all the way up to your chest and have straps that go over your shoulders. They fit snugly against your body and when you put a jacket over it that has an attachable powder skirt, like the North Face Allure, you can say goodbye to snow getting up in your business.
I'm a huge fan of the Bib made by North Face. For $399, I know it's a little pricey, but if you're big into winter sports, these will make your outings that more comfortable. I've had my pair for almost two years and they still look practically new, so I know they are well made. Since they're made with three layers of waterproof Gore-tex, my legs stay dry and the ankle gaiters keep snow from getting into my boots. They're really warm too, and all I need to wear is a pair of baselayer pants underneath and I can play in the snow for hours. If you're in the market for some new snowpants, I'd definitely consider getting a bib. Your warm and dry body will thank you.