I cannot do this. I just can't.

1.) X
2.) V, VI, VII, VIII, IX, XII, (X-2)
8.) IV, (XIII-2)
9.) XIII

No matter how hard I think on it I can't rank the middle ones. I would probably put VII ahead of the others but I can't even say that for sure. I love them all.

Note that I don't dislike XIII either. I like it, quite a lot, but in comparison with the other titles... it pales.