To answer the
OP i guess it depends on how you determine what makes a vehicle stand out from the rest.
Whilst many people shun the XF, if you were to ask a taxi owner from that era they will tell you without hesitation that it was the most robust and reliable model until AU, but if having a V8 option determines a cars value its a non contender.
The AU is considered by many as an ugly duckling but if you had to put your life on the reliability of a car i'd put it at the front of the list so for me i've always put XF at the top of the list because it was light years ahead of its time when cars were still unpredictable.
I've never been interested in cylinder counts so no V8 isnt a concern for me.
The worst would have to be EA as it just wasnt worthy of being a successor to XF in any way.
XF, AU, every other model in no particular order and then EA.