Not best, not most memorable, not toughest, not most architecturally sound... but ... favorite.
#11 at Kinloch. Par five...we played it from the middle tees, so it was a par 4.5. I flat-out killed my drive, had seven-iron distance left (needed six iron) hit seven iron, came up short, made 5 or 6 (don't recall.) Below you see a photo from the club's web site of the hole. There is a shallow isthmus of a second fairway to the right, but only a stick or a jester would intentionally aim for it.
Our fellow GCA'er, Kevin Lynch, aimed at the left fairway and hit a massive slider. As I recall, he had prefaced the shot by saying "only an idiot would aim right." The ball was little more than away when he began to encourage it to move more to the right...more...more. His enthusiasm was rewarded as the ball did indeed find the right fairway; we were tripled over amid gales of laughter.
Kinloch was my Augusta...caddies, immaculate conditions, solitude, a once-in-a-lifetime opportunity (thanks, LG) that I'll not repeat during this mortality. Although I drove the 4th and 2-putted for birdie and striped a 5-iron in to three feet on #7 for another chirper, #11 was doubtless my favorite hole of the year.