'Thriller' or 'Billie Jean.' 'Thriller' used to really scare me as a kid, but I loved it all the same. 'Billie Jean' was important for me, I refused to eat unless it was played on TV LOL. I also love Ben, that's a beautiful song.
For me though, the Michael Jackson I loved dissapeared years ago, after the 'Bad' album. He became known only for his eccentricities and odd life style/choices and not as an entertainer which I find very sad. It's also hard to seperate the two of them I find now.