I’m with Telemark on Summit County Colorado.
You can ski Vail, Breckenridge, Keystone and one other resort that is slipping my mind at the moment.
Basically, you buy your passes and you can ski any of the mountains. Breckenridge (my second home) has exellent accomodations and the shuttles are free. There are a lot of excellent restaurants (yep, even the 5 star places allow you to wear jeans) on the main strip of Breckenridge.
Shopping is high class too. Don’t feel like skiing? Lot’s of individual boutiques and high class shopping. If you want to go for the bargains? Take the shuttle to the Silverthorne Outlets, lots of name brand shops with great bargains.
Breckenridge has a good variety of easy to black diamond slopes (if you ski at Breck, hit Mach 1, it’s not the hardest but it will challenge your ability none-the-less), Breck has 4 mountains.
Keystone has 2 mountains with A Basin just up the hill from there (not part of the resort but if you are into serious high alitude skiing and the most incredible views, this is your side trip, may require a paid trip up as they aren’t part of the Breck/Keystone/Vail resorts anymore.)
Vail is usually a very crowded place but has some of the best skiing available and the town of Vail is a fun place for night life.
Copper Mountain has excellent skiing as well, it can get windy up at the top but the high speed quad gets you up there in a manner of minutes.
Over all, book your flight into DIA, tell your travel agent to get a shuttle to Breckenridge (I am serious, it’s the best place to stay) all you need from there is your skis, some cash and some clothes (of course you need a place to stay but that’s a given.)
Once the shuttle reservations are booked, and you arrive in Summit County, you have the world at your heals. And a damn good time to boot.