Of the alternatives in the poll, a night session at Arthur Ashe with the crowd going crazy, for me that's special. USO isn't the most well organized slam (only RG is arguably worse), but there's something about the atmosphere there.
Other than that, two things that I always enjoy watching:
1) A big upset. Out of nowhere, someone plays out of his mind and takes down a top seed. That sort of defines what sport should be about in my opinion. The belief that everything is possible.
2) A powerhitter painting the lines. Be it Soderling, Del Potro, Wawrinka, Thiem or in the future Sinner (knock on wood)... watching an in-form powerhitter crush the ball can be such a feast for the eyes.
In terms of venue/stadium only, I would have to go for Monaco, with the sea on one side, and the mountains on the other. It's so beautiful.
If we have to consider the tournament and the players, my 2 most memorable snapshots would be the beginning of the 5th sets during the Federer-Nadal Finals of Wimbledon 2008 and Melbourne 2017. It's such an amazing feeling to see History of the Sport being written before our eyes
And I think there is also a honorable mention that must be given too: seeing your country in an exciting 5th match of a Davis Cup final is something too. Home or away, indoor or outdoor, it doesn't matter much, it's a beautiful scene too
For scenery, hard to beat the setting of Micky CarIo & one of the few reasons to watch pIay on red dirt. For upcoming drama, perhaps one Iong awaited showdown at RLA between Fedovic to prove once & for aII who’s the king of AO.