And other oldies but goodies
Not on the importance level of DDT but:
Cyclamate- The best artificial sweetener ever made killed as a carcinogen in 1969. Now proven not a carcinogen but still absent from the shelves
Hexaclorophene- A really great anti-bacterial that was ubiquitous in bath soaps and antiseptic products until 1972 when it was killed as a carcinogen. Now it appears that no one can find any study that indicated it caused cancer in rats or otherwise. Still absent from the shelves.