I will admit that I am much more an internet expert than a skiing expert but I am an avid skier too- just stuck a billion miles from any mountains without many days to ski per year. Nonetheless, between studying trailmaps and discussion boards and visiting quite a few resorts, here are the ones I'd pick.
Whistler-Blackcomb. From what I can tell, they pretty much have everything except consistent snow at the base. 8000+ acres is nothing to sneeze at and its not an unreasonable distance from Vancouver to get to.
Jackson Hole- Again, pretty much has everything. Real vertical (4000+ feet), good lifts, good snow, great town. Big mountain with challenging terrain.
Vail/Beaver Creek- Two massive resorts close together. Vail has great bowls. Has front side and has Blue sky basin. Huge amount of terrain variety. And has great mountain base lodging, apres ski and dining. I've skied both and would go back any time. Beaver Creek seems to be under rated quite often. Its pretty darn big for a place that no one ever talks about around here.
Just up the road... Copper/Keystone/Breckenridge/A-basin. Got everything you need right there. Excellent tree skiing. Bowls. Steeps. Variety. Towns (breck, Dillon, Friscoe are all fun little spots to stay)
Let me stop and make a point that if you go on a big trip you want guaranteed skiing. Trust me, I know about this well because I do this every year. With these multi-stop spots you just can't go wrong. How can you not have a blast when you have 4-resorts within 20 minutes of each other? Which leads me to....
Park City, UT. Don't bother staying anywhere else in Utah. Park City is a great ski town. Everyone here talks up Alta and Bird all the time and for sound reason. But those two have NOTHING on the convenience of Park City. You have 3-mega resorts within 6 miles. Huge amount of skiing. Half of it practically walking distance with PCMR and Deer Valley back-to-back and The Canyons just a skip away. Can't go wrong. PC has Pinecone Ridge and Jupiter Peak if you want adventerous steeps. Deer Valley has variety and its fun to ski where the staff actually try to help you. The Canyons is great when there's lots of snow. So many peaks so little time. Can't go wrong.
Alta/Snowbird/ Brighton/Solitude- Another 4 resorts in Utah that are practically a suburb of SLC. Amazing terrain. True skiing. Incredible snow. I've only been to Alta of these four, but everyone here can tell you how great they all are. Its about 85% of all posts on this forum.
Big Sky / Moonlight Basin - One of my "must ski before I die" spots. I am a sucker for the lone peak type skiing like Mt. Hood or Big Sky's Lone Peak. Having a massive 4500 foot vertical ski resort on one side and another 4000 feet on another....unbelieveable. You can ski them both at the same time with one (ridiculously expensive) pass. But seriously- we're talking runs that are 3800 feet in vertical length from the top of Lone Peak thru snowfields and down into trees and valleys. That's just incredible. I gotta go there. Watch some youtube videos of Lenin and Marx from the top of Lone Peak- or The Big Couloir. Gotta ski that couloir.
Telluride - One resort. Remote location. But again- 4000+ feet of vertical with steeps, chutes, peaks and adventurous hikes galore. Not to mention skiing big vert down into a true ski town. Pretty much off the charts. The only drawback is getting there, and the fact that its maybe not quite big enough for a whole week. I'd love to go there for 3-4 days though.
Aspen/Snowmass - I have not been, but you get a lot of mountains (3+) and a lot of terrain with some really challenging stuff and still, great vertical drops. Problem with Aspen is you drive past a bazillion other CO resorts to get there.
Tahoe- 10 resorts. One of the most scenic places in the world. Incredible tree skiing. This is real tree skiing. Utah has nothing on Tahoe's giant tree skiing. Big ski resorts - Squaw, Alpine, Heavenly. Chutes and steeps at Kirkwood. Blue runs at Sierra or Northstar. First off the plane award for Mt. Rose. All of this and others are within about 1-1.5 hours drive. Stay in either SLT or Truckee and just have at it with tons of options. And you get gambling at the bottom of Heavenly taboot. Pretty cool.
Mammoth Mountain- honorable mention since its not their fault they are located in the worst possible spot. You have to drive past Tahoe to get there, unless you'r from LA or San Fran- then you have to drive 5-6 hours to get there. But from what I read and from videos I've watched it has an incredible single mountain just how you want a mountain to be- steeps up top above the trees, then trees down below all with a continuous fall line.
Lake Louise/Sunshine Village - Probably the most scenic spot in North America with two massive mountains in the Canadian Rockies. Its on my "must ski before die" list.
A lot of other great BC resorts but I'm not sure they are close enough to hit several at once. Everybody talks about driving from Spokane to Red, with the possibilty of hitting Whitefish and Schweitzer along the way- but I wouldn't do that if I could pick my other choices. Revelstoke has the big records but its pretty remote and I get the impression that unless you are going to do heli-skiing from there, its really not set up all that well yet. Panorama, Fernie, Kicking Horse - all three sound awesome. But for a trip its best to have many options in close proximity.
I don't think anything in the East can hang. I guess I'd say Stowe/Sugarbush/ Jay Peak as one option, and maybe Le Massif/Mont Saint Anne in Quebec as another. But I'd not choose either of those until I've gone on down my list pretty far. Unless its just for the French Canadian culture.
Probably a little long winded. I can talk about ski resorts all day.