I haven't been to any of those, but we're going to try somewhere in Michigan after Christmas too. What is the best place?
Where are you coming from?
In terms of vertical feet, from largest to smallest I think is: Boyne H, Boyne M, Shanty, Nubs, Crystal.
I haven't been to Highlands in years (probably close to 20 years now...). Boyne Mountain has a bit of a party atmosphere which is cool if that's what you're in to. Nubs is a commuter hill so there's not a wild scene there but it's a fun mountain with really good terrain parks. Shanty/Schuss I used to go there frequently hadn't been in several years and went back for a day last spring, I don't think it's as big as they claim and was kind of underwhelming but their terrain park is killer and it's a great family-friendly mountain. Crystal Mountain is my favorite even though it's the smaller of the bunch, superb resort amenities like a nice spa, several dining options, etc., which are excelled only by Boyne which has a waterpark and some other stuff. CM has a good vibe, really family friendly, park is lacking a bit but they make up for that with a good amount of gladed terrain and other stuff that's kind of unique for Michigan.