Have to go with Jackson. He's the most talented entertainer of all time. He could sing, he basically invented his own unique style of dancing, he was a bigger star for a longer period of time than Prince, when he was young he actually SANG his songs while dancing, whereas these people now all lip sync. He also made music videos into epic movie-style pieces of art, with Thriller and later Smooth Criminal/Moonwalker.
Everyone keeps saying Prince was a better musician, and that may be true, but Michael was a better entertainer.
Also, this is subjective, but for my taste I never really got into Prince's music. He has a couple good songs but I actually like MJ's music better.