Alrighty, Sanctuary and Pradera.
Both courses have quite a few interesting holes, although I would argue Sanctuary has a couple more. At Sanctuary, the 1st is a great opener although its a little penal for a first tee shot with lots of opportunities for a lost ball right out of the gate. The 4th is another fun par five with definite risk/reward potential, the 8th is the original of one of my favorite Engh template greens, and the 9th with diagonal bunker really creates an interesting tee shot. On the back, I don't like the 11th, but the 12th is one of my favorites especially with the tee shot, and the 13th and 14th are solid as well. The 15th I like except for the bunker wrapping around the water. The 18th is a pretty decent finisher although somewhat typical in that its uphill. The course is very challenging, has good risk/reward opportunities early and often, is obviously very aesthetic, and has a high fun quotient. Its certainly not walkable.
Pradera has a lot of the same good qualities. I don't find the design quite as interesting as Sanctuary, but its by no means a huge gap. Its more playable than Sanctuary and Engh used some features that I haven't seen on his other courses. The 10th green is a nice change from the bowl shape (think bowl upside down somewhat). The 16th is a fun tee shot where I hit my all-time longest drive with a 30 mph helping wind (480 yards and I only outdrove a playing partner by about 30 yards). The split fairway 7th doesn't work as well as it could to me because the right fairway is so narrow and such a long carry that it doesn't make sense to try it in a stroke play situation to me. The gap with Sanctuary to me is the water holes at Pradera that remind me more of ho-hum Florida than Colorado--the 8th comes to mind. I remember water on the 9th but not much else, and the 18th is a decent finisher par five but not as good as Lakota Canyon or Tullymore in terms of risk/reward finishers.
I like both courses quite a bit--Sanctuary gets the nod but Pradera is well worth playing as well.
If we're eliminating courses outside the mountain time zone then Sand Hills is out too--I seem to remember it being in the original list.