I go to Steamboat.
For day trips with friends we go to either winterpark or a-basin.
There is a Wells-Fargo deal with Christy Sports where you can get 2 for 1 ski passes to Copper/Winterpark and can add on days at Steamboat. You have to be a student, you set up a student account at Wells Fargo and they give you a voucher that you take to Christy. A lot of my friends do this deal.