The nominees for 1968 was two musicals (Funny Lady, Oliver!) Two costume dramas (Romeo and Juliet, The Lion in Winter) One Drama (Rachel, Rachel)
The Question is which would have been the next five.
"2001: A Space Odyssey" earned a director nod and is one of the ten. The same goes with "Battle of Algiers".
Now there's three slots left. One of the nominees would certainly been the big flop musical "Star!" it earned the great amount of 7 nods. Next is probably "Faces" with three nods.
The Last nominee would been "Rosemary's Baby". This classic horror movie earned 2 nominations but neither of them was for Mia Farrow :(
With these ten I also leave out several classics like The Producers, Bullitt, War and Peace, Planets of the Apes, Belle de Jour and...
The Good, The Bad and the Ugly
The Ten Nominees
2001: A Space Odyssey
Battle of Algiers
The Lion in Winter
Romeo and Juliet