NYCB has some of the best (obviously). Charles Askegard, Albert Evans, and Philip Neal are in my opinion their top three right now. Jock Soto (as mentioned above) was one of their top principles until his retirement. The best I’ve ever seen was Peter Boal who left NYCB a few years ago and is now the director of Pacific Northwest Ballet in Washington.
I will admit to a bias toward NYCB as I live near the Saratoga Performing Arts Center in Saratoga Springs, NY and have seen many performances. Also my daughter’s ballet master for many years was once a principle with NYCB when George Balanchine was the director (in the 60’s).