The Aztek will probably go down in history as the ugliest car, knocking the Edsel out of the top spot.
As for the Dodge Monaco/Eagle Premier/whatever else they were badged as, to me, it's not "ugly" as in the car itself, it's that the area was the '90's and everyone was on the "aerodynamic" push. Low hood lines, rounded edges, etc. This car, being boxy, didn't represent the "best" of the era, especially considering it was basically a re-badged Renault.