Castle Pines GC definitely qualifies for me - my expectations were, shall we say, tempered but I came away feeling it is one of Nicklaus' finer designs, rivalling but not quite matching Muirfield Village. CommonGround would be my runner-up choice - lots of architecture out there considering the budget.
On the other side, I felt let down a bit seeing St. Thomas G&CC just outside of London, Ontario for the first time. It's a noted Stanley Thompson design and while I can appreciate the layout if I squint hard enough, my overriding impression was shock at how badly they could use a chainsaw for overgrown trees on a number of holes, both to open up playing corridors and to give much needed sunlight to areas of need. I understand that they are working on that problem and hope to see the course again when they are finished with the project.