The show that turned HBO into HBO as we know it today, Tom Fontana's drama about an experimental prison unit is among the most graphically violent series in television history, but also among the most thoughtful. The cons of Oz didn't just find creative ways to torture or kill each other; they debated race, addiction, sexuality, religion, elder care and whatever topics were on Fontana's mind at the time. "Oz" broke every rule in the book about the necessity for likable characters, about minority representation, storytelling structure, and a lot more, and it made it possible for HBO to try "The Sopranos" and every show that came after. Looking back, "Oz" is a little more conscious of its status as a trailblazer than some of the shows that followed, but overall the writing, direction, and performances by an absurdly deep cast — with Lee Tergesen, J.K. Simmons, Chris Meloni, Eamonn Walker and Adewale Akinnuoye-Agbaje as a few of the many standouts — transcend whatever might feel dated as a result of all the shows that followed.