When coming up with a list like this, a few thoughts come to mind.
One, it's very generational. While this list includes US Open performances going as far back as 1913, I will always be biased to what I remember watching. Anyone will.
So because there have been so many great rounds, there really are no right or wrong answers. Compiling this list, I looked at great rounds that I excluded, or ranked low, and was amazed.
There really are no special provisions for this list. It's not necessarily the 25 lowest scores in US Open history. On that note, some of the rounds included weren't even the top round that that golfer carded on that given week.
Some rounds are included for more than just score. Maybe a golfer held off or caught legendary golfers, maybe a golfer was only a shot or two under par while the rest of the field was struggling to break 75.
Obviously, score is a factor. Some of these rounds came before the final round. Heck, some of these rounds weren't even carded by the eventual winner. It's an undeniable factor, just not the only one.
And on the note of having no wrong or right answers. I don't apologize for what rounds I included here or the order that I put them in.
By the same token, someone else could compile a list that looks entirely different and have nothing to apologize either. It's just what happens when we have more than 100 years of history to draw from.
A special thank you does go out to all of The Bleacher Report's golf writers who offered their suggestions.