I see a few have nominated #13 PVGC. That hole is really hard to par for anyone who doesn't hit it long. But there's an oddity about that hole I've noticed over the years--that being the tee shot. The hole is a long one (about 460) but long hitters rarely seem to use driver there anymore (the reasons are interesting) and consequently seem to leave themselves a bit too far back for their approach sometimes. The hole may be scheduled for lengthening by 20-30 yards (as Crump intended) and in my opinion might end up making that hole easier to play for the long hitter as that might be just enough take a long iron or 3 wood on the tee shot out of their hand (Holman's hollow and the subtle nature of the topography just past it!) and put the driver back in their hand!
Tom makes a very interesting point, but one that needs even further clarification. A prominent reason this hole remains so difficult, and long is that the tee shot needs to find its home in a relatively narrow landing zone to even offer up a reasonable, if lengthy approach to a tought to hit green. nearly all the shots (often inc. the putts) need to have a draw component. The tee ball, if drawn, must start out at a spot that if hit perfectly straight, will likely leave a partially blocked out apporach. If overcooked, the fairway cant will leave only a lay-up. The ultimate fairway zone is only about 30 paces wide and considerably defended by rough at the far end, and blocking trees and brush on both sides....thus making the drive the stiffest test of any PVGC four par.
The approach is no day in the park either. Again, a draw of never less (unless your last name is Kuene or Woods) than 185-195 yards is required and must land on the side fron to the green in order to hold and put a putter in ones hand. The hollow and surrounding bunkers are miserable places to look at hitting from and thus most PV caddies correctly advise laying up to the ample area right of the green. If a lay up is played, one quickly, if smart enough to carefully look, sees a sloping away green that is usually way fast...thus producing perhaps the toughest 4 par (w/out any extraneous factors such as wind, technology, etc..) out there.
Although tough, it is one of the MOST fun 4 pars anyone could ever play, because ANY par feels like a birdie and any bogey feels like a par....even more than any other PVGC par 4.