Oz

From Wikipedia:

Oz is an American television drama series created by Tom Fontana, who also wrote or co-wrote all of the series' 56 episodes. It was the first one-hour dramatic television series to be produced by the premium cable network HBO. Oz premiered on July 12, 1997 and ran for six seasons; the series finale aired February 23, 2003.

Oz is the nickname for the Oswald State Correctional Facility, formerly Oswald State Penitentiary, a maximum-security prison (level 4) at an undisclosed location in the United States of America. Many of the plot arcs are set in "Emerald City" ("Em City"), an experimental unit of the prison in which the unit manager attempts to emphasize rehabilitation and learning responsibility during incarceration. Emerald City is an extremely controlled environment where there are a controlled number of members of each racial and social group. 

The large ensemble cast includes Eamonn Walker, Rita Moreno, Ernie Hudson, John Lurie, Terry Kinney, Betty Buckley, Kathryn Erbe, Christopher Meloni, Lee Tergesen, B. D. Wong, J. K. Simmons, Dean Winters, Scott William Winters, Kirk Acevedo, Adewale Akinnuoye-Agbaje, Harold Perrineau Jr., Erik King, David Zayas, Lauren Vélez, and Edie Falco.

Oz is primarily narrated by Augustus Hill (Harold Perrineau Jr.), former drug dealer, convicted murderer and former crack addict. Now in a wheelchair, he appears in surreal segments and introductions that usually relate to an overall theme of the episode, as well as setting up scenes, introducing characters, or adding epilogues. When necessary — usually when a character is introduced — Hill appears as an omniscient narrator. Used as a literary tool of the writers, he narrates the details of characters' crimes, their prison number, and their sentences. Hill appears as a recurring character within the show's story lines until the sixth season, in which narration by various deceased characters was added.