Boards
Guess what the 2nd most successful original album of all time is, according to Wikipedia.
So yeah, Thriller is number 1.
There are two albums in the number 2 slot but one of them can safely be discounted. Even the third one should probably be dicounted.
http://en.wikipedia.org/wiki/List_of_best-selling_albums_worldwide
Anyway, I was surprised. Also of surprise is how Thriller can be almost three times as successful as the next most successful album. THREE TIMES.