My best portrait lens was 6 lenses.
One lens can't do all the portrait types there are: groups, environmental, studio, on location, children, fashion, corporate, model/actor, and more.
24 mm f/1.4
50 mm f/1.4
85 mm f/1.4
105 mm f/2 w/de-focus control
135 mm f/2 w/de-focus control
and 200 mm f/2