David Hamilton and Sally Mann for young nudes. But in the current witch-hunt atmosphere I wouldn't be caught dead in possesion of this stuff, doubly so if I were a teacher.
Mel Killpatrick for his 50's car crash shots (discovered posthumously in the 90's).
Diane Arbus for the mental patients (more posthumousity).
EJ Bellocq for the Storyville prostitute photos (photos that he mostly loathed and destroyed later in his life) Three in a row for posthumous publication--his 89 remaining plates were discovered, publicized and published by Lee Friedlander over 50 years after they were taken.
Alexander Gardner for the moving-the-dead-soldier-at-Gettysburg incident.
I might vote against Nan Goldin--seems to me the only controversy there is insipidity vs. art. But if you will admit this sort of controversy Friedlander, Winogrand and Eggleston are probably candidates too, although I personally like all three far, far better than Goldin.
David Armstrong and Uta Barth for veering outside the constraints of focus.
Leni Riefenstahl and Tina Modotti, although both were controversial mostly for their politics rather than their photography.
Jacob Riis for his expose of turn-of-the-century poverty and squalor.
Tom Forsythe for the Barbie photos that got Mattel cranky enough to engage in protracted hopeless litigation just to hurt him, to cost him a great deal of time and money merely to warn others that Mattel was not to be messed with.
William Mortensen for the way he (and other pictorialists) were savagely attacked by Ansel Adams and other our-way-is-the-only-way f64 adherents.