I have very fond memories of this venue from having seen Phish there 5 times. Best in the nation? Eh, rankings are bs anyway. Lawn is surprisingly shallow but occupies a wide arc, so sound is good but sight lines maybe not so much because it gets crowded.
https://www.timeout.com/newyork/news/this-new-york-amphitheater-was-just-ranked-the-best-outdoor-music-venue-in-the-u-s-061025