Having been to Whistler/Blackcomb every Winter since I learned how to ski I'm really enjoyed Whistler. Aspen/Vail resorts just don't "do" it for me. I second the opinion that Whistler is more fun and attracts a younger (MUCH younger) crowd than Aspen in general.

The Whistler Village is also very well planned, and you can basically walk to everywhere there's parties. The Fairmont is right on the base of Blackcomb and offers unparalled view of the slope. It's by far the better hotel having direct access to the slopes. There are also many ski-in/ski-out vacation units by IntraWest on the Blackcomb slopes. I personally prefer Blackcomb to Whistler, although for me a 5 day ski week I'll usually dedicate 1-2 days to Whistler for its more fun runs.

The drive to/from Vancouver is rather painless, if you go there during the right hours. Heli rides are also very short and readily available.

I highly recommend Whistler "Altitude" over Aspen....

The icing on the cake is the USD > CAD exchange rate.