Repeated from the Mountain Collective thread:
6 Jackson Hole
The common denominators here are 350+ inches of snow and expansive terrain. The two that don't have a lot of steeps (Vail and Bachelor) have enough other compelling attributes IMHO. Jackson would be #3 if it faced NE instead of SE. For those areas not on this list due to lower snowfall, my opinion is that steep terrain and less than 300 inches snowfall means that that said steep terrain is not consistently open (Crested Butte is the poster child here), and the reality is that days with 6+ inches of new snow are comparatively rare if powder opportunities are important to you.
With regard to Whistler and Jackson snowfall numbers, 2 important factors to keep in mind are:
1) How many years of snow measurements?
2) Where on the mountain are measurements taken relative to actual ski terrain?
Long term (~40 year) averages are 419 inches at Whistler 5,500 - 6,000 feet and 371 inches at Jackson 8,250 feet
The 469 at Whistler is over the past 10 years. Snowfall is volatile; 10 years can still be a short enough time span to deviate from a long term average. Probably 90% of W/B ski terrain is in the upper half of its vertical, so a high measuring site is reasonable.
The 459 at Jackson is from the top of the Bridger gondola since 1998. Jackson comes to a peak at the top and fans out for miles at the base. There is much more ski terrain below 8,250 than above, so the 8,250 site (besides being many more years) is the appropriate measuring site from a skier's perspective.
Whistler is extremely consistent and reliable for snow. If I knew I was getting a powder day, would I rather be at Jackson, given water content of snow and probably lower skier density? Of course.