Ok, here's my list, only in states where I've skied enough of the majors enough times to have formed a real opinion.
Vermont: I agree 100% with Liam about Sugarbush and the trails on Castlerock, especailly Rumble.
NY: Gore: I also find Whiteface to be kind of boring and overated. I skied Gore for the first time in a long time this season and I like it better. There is also a lot of potential for expansion of terrain there.
NH: For me, a toss-up between Wildcat and Cannon. I think with the Tram Line and other shots opened up from the top now Cannon takes it.
MA: I have to go with Jiminy Peak.
CT: Mohawk ( just boarded there yesterday)
UT: Alta. (but I like the Alta-Bird idea) I skied the dual ticket the season before last and really enjoyed it. We hooked up with some friends at Snowbird and skied with them all morning, then my partner and I slid over to Alta and hiked for fresh tracks all afternoon.
CA: For me it's either Mammoth or Squaw. Hard to decide. I'm gonna say Squaw because I think there is a little more variety there.
CO: I've skied all the major areas except for Steamboat, Aspen and Beaver Creek. Of the rest I'm gonna say Vail. Not the steepest, I know, but I've had some great days there exploring huge bowls of untracked snow and that is a lot of FUN!
I think WY and NM are obvious.
Haven't skied Idaho at all, nor Washington, nor Oregon.
Haven't skied Montana or Canada enough to have any opinion other than that I need to do more, ahem.... research!