We talked about this earlier, and I was sure Thriller would surpass the Eagles: Their Greatest Hits 1971-1975 with Jackson's death, but I was wrong. As of now, they're currently tied. According to the RIAA, which published its updated numbers about a week ago:

Quote Originally Posted by RIAA
Michael Jackson’s legendary album Thriller (Epic/Legacy, 1982) has now climbed to 29x Platinum to tie the Eagles’ Their Greatest Hits (1971-1975) as the highest certified album in RIAA Gold & Platinum history. This extraordinary achievement by the King of Pop is a testament to his enduring legacy and the unequivocal imprint he has made on the world of music.