I have a tie. My two (from the back tees) are:
Sand Hills #4. Long, great approach, great green, 3 story bunker for approach shots missed left...almost fatal. Ground game open in front. Elevated green pitched from back to front. Backstop for shots missed right. Par is a victory! VCH = Very Challenging Hole
Dismal River #18 Visually outstanding! Long uphill drive, leaves opportunity (even for us old guys) for long uphill second shot to reach her in two, or a layup. Ground game open to right and rear. Downwind - a 4-1/2. Great ending. VFH = Very Fun Hole.
Both can go from relatively easy to excruciating where par is a challenge, mostly due to wind. Multiple personalities!