It is very hard to define the "most beautiful" holes in terms of golf.
If it means picturesque, then there are a number of WGT holes that would be contenders, but in my opinion, this would exclude the links courses.
Many would say the links "rugged beauty" might put them into contention and as mentioned beauty is in the eye of the beholder.
As much as I idolised Payne Stewart, I am not sure if this would be a reason for contention. Another scenario is playing in a group with SP, strong winds and a short skirt......as much as I am sure I would enjoy the game, would it then necessarily rate as a beautiful course? Stunning vistas perhaps! :)
You could have the most picturesque course that is just a pitch and putt; would this be worthy of contention?
Beauty coupled with difficulty must come into the equation - like a woman, beauty and brains is a must (although I am certain Mr Stroker will deny this lol).
Each time I have played the Old Course I have had goose bumps walking to the first tee but none of the holes would rank for me, and that is in no way demeaning the course. Not sure how I would handle walking up to the tee at Augusta, a quivering mess no doubt lol.
I have been lucky to play some great courses around the world, some with stunning memories, but most courses are so different quantifying beauty is too difficult.
The word beauty is too contentious as often with "beauty" we are not objective.