Oz
The best series I've ever seen, by far.
It's mature, incisive, addictive, violent (in every sense of the word, you have to be ready to take it in the face and the feelings), without any taboos, very well acted, very well written, it's... more than TV.
The characters are more accomplished than in any series I've ever seen, and no one is all black and white: Tim McManus, the man who came up with the idea of Esmerald City and is in charge of it, is basically a good guy who sincerely wants to help the prisoners, but that doesn't stop him from being the worst kind of asshole at times. We're locked in with rapists, murderers, gang leaders, losers, basically the scum of the underworld; but we can't help but get attached to them, and we end up like idiots over the course of the seasons, having our favorites, adoring characters who are objectively sickening, and being literally grabbed by the guts when something really bad happens to them... No one is spared, and it would be better not to get too hung up on the characters, but frankly, that's impossible. When a character arrives at Oz, it's impossible to know whether they're there for 3 seasons, 3 episodes or 3 minutes. Sometimes we linger on a character for a few episodes, just long enough to get attached, and then he dies stupidly, collateral damage in a fight that was none of his business.

What I like is that the series never tries to justify their actions or make excuses for them. They're all guilty (or almost guilty), there's no doubt about it. When they arrive in jail, we see them commit the crime that led to their conviction. They're criminals, period. Now, what are we to make of them? Are they irredeemable monsters, or can they be reintegrated into society? Oz doesn't give us a ready-made, naive answer, and frankly, by the end of the series, I was even less sure than at the start (and the film Boy A didn't really help the matter).
We “ arrive ” at Oz at the same time as Tobias Beecher, a normal guy who's there more out of misfortune than anything else (he's still guilty, of course, but he was convicted heavily to make an example), and that's our gateway into Em City, the only way we can identify a little at first... And then, once we've watched all 6 seasons, spent a few years with them, we realize that our outlook has totally changed, and that we've evolved just as much as Toby. We feel like we've been one of them, and we're pretty proud of it.
Adebisi, O'Reily, Kareem Saïd (the most charismatic guy I've ever seen, without any hesitation), Augustus Hill, Miguel Alvarez, Doctor Nathan and Sister Peter Marie alone make Oz worth the detour!
