My opinions come from the back tees and tourney greens:
#6 at Merion: I bogey this hole (back pin) more than any other on WGT. Have no clue how to play it. *** green. Might try laying up and just going for par next time. When I par this hole, I run to the 7th hole super happy.
#9 at Oakmont: Get on the wrong side of the green here and you'll have a sure bogey or worse. Can occasionaly birdie this hole, but that is very rare. Par and I'm happy to escape.
#5 at Merion: Another *** green that is hard to get an approach close. Very fine line between hitting the green relatively close or watching your ball rolll down the hill. Back pin might be more nasty than the front. Haven't played the back enough yet though.
#17 at St. Andy: Back pin location is a ***. Strong tailwaind and it is next to impossible to hold anything close. Strong headwind leaves me without enough club for a birdie chance. Another hole where I'm thrilled with a par.
#2 at St. Andy: You know what pin location...Usually well past the hole even after a seemingly good approach shot. I'm sure there must be a sweet spot on the green to land the approach to keep it in birdie range, but I have yet to find it. Only chance here is a headwind, but the green is also very nasty if you get on the wrong side.
#7 at Bethpage: Front Pin...Have birdie this location only once. Par is usually easy with 2 good shots, but a birdie is next to impossible.
#5 at Olympic: I own that effin tree branch. Surprised it hasn't fallen off yet considering how many times I have hit it! Depending on the wind, I have resorted to punching my driver to hit the fairway which leaves a 3 iron or 3W approach to a tricky green.
#18 at Merion: I usually end up with a strong headwind and a very long approach shot that isn't receptive to holding the green. Usually thrilled with a par on this hole.
#1 at Olympic: This hole can break the spirit of many players right off the bat. Can be a *** depending on the wind. Hitting the tree here is always a possibility. Over compensate and you're in deep rough and looking at a probable bogey. Often times, I'm just happy to escape with a par and move on to the next hole.
#15 at Congressional: Birdies are very rare here because of the long and elevated approach shots. Very difficult to hold the approach close and even if you do, you'll probaby end up with a tricky birdie putt.
There are others, but the 10 above are the holes that I'm most likely to bogey and least likely to birdie.