Since each site is different, in theory every course (except for perhaps copycat or template courses) are unique in golf, no?
That said, any spectacular site tends to stand out as unique, whether the ocean views or big dunes like Cruden Bay, etc.
As far as design, my first impression is that Strantz stuff is the most unique by far. Dye stuff was that way when Harbor Town was built, but given copycat (or general design trends) unique designs have a way of or at least potential to become less so over time, whereas site qualities never change (without some major erosion, forest fires, etc.....)