i hear Winter Park is epic for freeriding/downhilling.i live in crested butte and our lift access dh is pretty sick, but not on the level of keystone or winter park. we just hosted the mountain states cup and the pros were running about 4 min. times. there is some pretty sick north shore style stuff here and there is a super techy trail called psycho rocks i shit bricks every time i try to ride.
if you can do shuttles to the top or dont mind riding some uphill, the trails off the resort are epic, and the single track is some of the best in the world