Mine is a no brainer, though it is actually two holes rather than one. And to compare the way they intimidated me to the 85 Hoyas doesn't really do them justice. Imagine that you were held up at gunpoint on your way to work the very first day of a new job and you arrived to find out that the one doing the mugging is your new boss. That's more like the intimidation I'm talking about.
I joined the men's club at Rolling Meadows in CT for most of the 5+ years I lived there. #14 at this course is a short par 5. The best I ever did was a 4, the worst I ever did was a 14, and I damn near made every score in between. The hole has thick woods running down the left side. Usually not a lost ball, but not fun to get out of either. The right side was also wooded, but has out of bounds not too far in from the treeline. #15 was a beast of a hole. A long par 4 that had a subtle dogleg and also got the narrowest right where you wanted to hit your drive. The green was tough to hold, and very sloped. In 5 years playing fairly regularly at that course, I only made 2 pars on that hole and both times I was hitting a three wood approach (the hole wasn't that long, but I didn't always hit driver and I didn't always hit the tee shot well!)
I shot the best score of my life at that course - 76 - and I went 7, 7 on those two holes that day! I used to try to plan a strategy for those two holes every time I went out. They were always in my head. I had a co-worker that knew about the effect they had on me, and he would get me thinking about them a few days before I'd play on the weekend. He loved to hear the blow up stories on Monday.
I've played much harder holes in my life, but I've never been more intimidated by any. I'd have taken 6 - 6 on those two holes before I started my round any week, and more often than not I'd have been doing better than when I actually played them.