I'll jump on Ran's bandwagon and re-nominate Muirfield. Very, very flat ground, four par 3's that played the same length, #9 was interesting and fun to play but #17 was a little bit of a letdown--drive was un-inspring but the second shot did have a "pucker-up" factor. Even #18 green seemed "small"?
My favorite hole or shot was the tee shot on #11--blind up over the hill and then a tough little green with a deep bunker right--that's more like it!! Anyway, I think most of the guys I played with (the Americans anyway) hated that hole! I also loved #6--downhill dogleg left with the death bunkers on the left and the wall short and left.
Other nominees--Oak Hill. Very nice although I thought #13 with all the oaks around the green may have been one of the weaker holes.
Upper Cascades (qualified for 88 Amatuer and was bummed when I got there--missed Merion by one year!!) Also played the Cascades in 2 more tournaments and other than #9 I still don't "get it". 5-5-3 finish is interesting but it still a long ass drive for a great "mountain course".
Stanwich in Conn. is very nice and immaculate and I haven't seen the course since the renovation but it seemed like EVERY shot was to a green, pitched sharply from back to front with bunkers on each side. Under the hole is fine, pin high right or left and you could three putt 10 times!!
East Lake--back and forth parrallel holes that got more vanilla post renovation. (Maybe I just long for the days when my clubs were stolen from the 1st tee as I stood 35 feet away! At least there was some excitement
) The Jones' memorabilia inside the clubhouse is 100x more inspiring than anything outdoors.
Walton Heath--after holes 1, 2 and 4 (dogleg left with the wildly undulating green) it kind of a snooze.
I disagree a little with Hoylake. I played terrible and the surrounds are ugly but the cops on #1, #7 and #16 and the road tight to the green on #17 were very interesting. The land is far more rolling (#8, #9, #10 particularly) than Muirfield for example. I'm not saying it is great, but I think there is more there than meets the eye.
While Winged Foot West was mentioned I have always been impressed and inspired by the sheer bigness and scale of the course--big bold greens, big deep bunkers, big clubhouse as you come down 9 and 18. Just a big, awesome beast. Looking down on a grille placement mat, it looks repetative (long par 4--bunkers left and right) and yet I can't think of two holes that play the same or two greens that look alike.