Snowmass is the best overall moutain there. If highland bowl at highlands is open it is worth going there and doing the hike. The views from the top of the bowl are amazing. Steep lines out of there.
Aspen mountain is fun to do. It is decent atthe end of the day you can ride right to downtown Aspen walk across the street and get a beer. Urban ski area. Pretty kewl.
Unless you want park skip Buttermilk. Buttermilk sucks...