Since there seems to be a lot of skiers on here, Liberty, Roundtop and Whitetail are all owned by the same company. They are all about the same time/distance from StMary's. They are all day trip ski areas (no lodging) although I remember reading somewhere about maybe a hotel or soomething being built at one of them. I prefer Roundtop for the way it's laid out. Facing the hill, the easiest is on your right and gets more difficult as you move to the left. However, most of the trails/slopes are interconnected so if you are skiing with a group of friends and not everyone is the same level skiier, you end up at the lifts together. I don't care for Liberty the way it is laid out (front and back of the mountain). Whitetail always seemed to only have about 1/2 the slopes opened when I was there.
Never made it to Snowshoe (don't think you can get there from here) in a reasonable amount of time for a weekend trip.
Haven't been to Wisp for over 20 years, thanks for the link to their site. Looks like a lot has changed since then.
7 Springs has been our 2nd home for 20 years.
See ya there