We live in Boston and I'm wondering if you guys know of any flight routes that are reasonably priced, like if there are airlines with hubs in both cities or something. Ultimately it'd be good to have a comparison of the whole package in any one place - for example, flights to Denver are generally cheaper than to SLC, but I'm told lodging can often be found more cheaply in SLC, and we'd probably have to rent a car in Denver? Tahoe would also be good because we can rope in friends from the Bay Area, haha.
Direct flights to DEN are relatively cheap and plentiful. Delta seems to be running a limited number of BOS-SLC nonstops now. Any other ski destination requires a connection from Boston. Try a site like Kayak to compare multiple airlines (note that Southwest doesn't show up on search engines). Pricing can vary wildly depending on how far out you book and how popular a destination is at different times of the year.
If you're going anywhere with a big group for a week+, consider that renting a house or condo may be cheaper and/or nicer than getting multiple hotel rooms. Getting a place with a kitchen can save you a lot on food.
As mentioned above, you'll pay less in the early (before Christmas) or late (after February) season. Late season is generally more dependable. In terms of snow quality it's best to book things as late as possible, but you might find you can't get cheap lodging and lift tickets at the last minute.
Group trips vary too widely in terms of setup and pricing to give an easy answer or recommendation.
If you ski the Cottonwoods areas (Alta, Snowbird, Solitude, Brighton), you can stay pretty cheaply in the SLC suburbs like Sandy. There are also some buses up to the resorts. I rented a car when I was out there. Limited apres.
In the Park City area (Canyons, Park City Mountain Resort, Canyons) lodging is generally more expensive. It's about an hour drive out from SLC. Park City is more of a hip ski town as opposed to an industrial slum like the outskirts of SLC.
From DEN it's 90-120 minutes up to the Summit County areas (Vail, Beaver Creek, Breck, Keystone, Copper, A-Basin). You can get shuttles to take you up and back from the airport, and there are some buses, etc. that go around between towns and resorts, but a car is easier. Lodging varies, as does apres. If you want to be very close to a resort you'll probably pay more than in SLC, but things are more reasonable in the Dillon/Silverthorne area.
Aspen is pricey and a long haul (4 hours) from Denver. But really nice. Aspen itself is a cool town, and you can get by without a car if you stay somewhere near the shuttle routes to the ski areas.
Tahoe's kind of a pain to get around without a car. If you stay in Reno or Carson City lodging is cheap, but it's an hour+ back and forth. Near the lake it's more expensive. Again, pricing depends on how far you away you are from popular destinations. Apres/evening entertainment is probably better around Heavenly, what with the casinos in South Lake Tahoe.
The major resorts at Tahoe are split between the north shore (Squaw/Alpine, Northstar, Mt. Rose) and the south (Heavenly, Kirkwood). When there's snow the route around the west side of the lake closes, making it a longer trip between those areas.
Whistler's another option. Haven't been there. Hear it's awesome. Lots to do. No idea on housing costs, but I'm guessing expensive if you want to stay close to the resort itself.