Easy to get to is definitely won by SLC. I just moved to SLC this past summer and driving to the resorts is typically less than 40 minutes for Brighton and cottonwood canyons. From my house it's about 25 minutes to Park city and Canyons..
Besides that I can't help too much. I would guess SLC will beat Denver for all but nightlife. IMO if you're making a trip to board that should be low on the priority list. Easier to visit multiple resorts here without as much driving since Brighton and Solitude are right next to each other, Park City and Canyons are next to each other.
When I stayed in Denver for a trip last winter, it took me and my buddy two hours to get from Denver to Keystone/Breck....