I read the majority of the comments and I noticed a lot of people say "to me Hyoyeon the prettiest" or "Yuri and Seohyun are prettier" or "Tiffany is" etc.everyone mentions a different member each time which only proves that in SNSD. You can say X is the prettiest and still find hundreds who would agree with you. Simply because they're all attractive.
That being said, lets just respect Heenim's opinion instead of saying that another one is prettier and then get all defensive when someone doesn't respect YOUR opinion.