My top short par-4 is the 6th on the St Olaf course at Cruden Bay. Hit, if you can,over a blind, narrow saddle, it's a pretty long hit though, turn half left and play onto a green built on a shelf in the side of a dune. Go left of the green and it's gorse and jungle, go right and it's a severe drop off. It's about 350, but it's not drivable so my nomination is....
........the 18th at TOC.
Honourable other mentions, 3rd at Carnoustie and 18th at Kington.
Nice post.
All the best.