Knightfall
World of Kulan DM
Quite a few, actually...Out of idle curiosity..how many products of monsterness did Mayfair put out?
TSR Dungeons & Dragons Archive: Role Aids
The main monster books/folios are the Monsters of Myth and Legend books and the Demons expansion folios. I'm not sure how many monster entries there are in the other accessories and boxed sets, but I'm sure there are some in those products as well.