My ugliest was probably a 1962 Dodge crew cab. It was an ex Air Force flight line vehicle and was still that crappy AF blue with all the official numbers premiered out.
While ugly, it was a great truck. A beast.
My coolest might have been my 1965 Plymouth SAtellite convertible.
My worst was maybe my 1968 Caddy Sedan de Ville. Always had to work on it.
This list is open for revision. As I've mentioned before, I've had over 40 vehicles, some for only a few days or week's, so I'll probably remember others.
These are the ones that popped into my head.