There's one important decision to make when shopping for ski pants—or ski jackets too, for that matter. It is: Insulated, or uninsulated? I am firmly in the uninsulated camp. I like to be able to make a call at the ski area about whether to add an extra layer under my ski pants or not. I usually find that a pair of midweight wool tights (Icebreaker Bodyfit 260 Legging, $85) is more than adequate even on very cold days.
For several years I've worn a pair of Patagonia bibs that are fantastic, but alas, no longer available (enormously complicated pants to stitch together, which made them pricey). Patagonia's current top-end ski pant is the Power Bowl Pant ($299). They're nice ski pants, with tough polyester fabric with a water-repellent coating and Patagonia's very fine H2No coating, gaiters to keep snow out, and reinforcement where ski edges cut into them.
In a bib, take a look at Marmot's Randonnee Pant ($350). I like the high cut of bibs as they're warmer and more snow-proof than pants. These are made from Gore-Tex Pro Shell, which is really nice stuff. They also have scuff guards, internal gaiters, and zippered handwarmer pockets.
And, you always can count in Arc'Teryx to come up with something that is über-expensive but so well-designed and well-made that they seem like an über-bargain. The Theta SV ($425) is a simply gorgeous bib pant, made from Gore-Tex Pro Shell. It has waterproof zips, two convenient bib pockets, power cuffs, and some stretch where you need it. Beautiful.