From a music & choreography perspective, Jackson was brilliant. His songs and in particular his arrangements of rhythm, bass line and pad, were simply inspired...some of them were the "zz-top" of pop, even the most ardent of non-fans sometimes has a subconscious toe-tap to his beats.
His dance moves were similarly very well done indeed, many of which have their roots in older moves but combined with his signature "spasms of precision" technique, have meant that it's become a dance genre all of its own.
So, love him, hate him or indifferent - one has to respect his talent. As for his private life, no comment - I resist making any judgement without knowing the facts.