I ski Alpental and it's defiantly not the hardest marked inbound area, considering it's two lifts tall and has extremely limited terrain. The only reason that it is difficult overall is because of the lack of snow we seem to receive year after year, resulting in almost constant icy conditions.
As for the hardest inbounds run, has anyone said Spanky's Ladder, Blackcomb/Whistler yet? That is one ballsy run.