They really stuck the landing on the ending. My favorite series finale ever. This show is the first show I've ever watched live every week from the pilot to the finale, so it definitely holds a special place in my heart. The golden age of TV is now over, folks.I was confused by the ending. Is it fair game for you to explain it to me (why Saul made the choice he did), without it being a spoiler to others?
Saul is an embodiment of pure selfishness and greed. He's always working an angle. His direct downfall is because he decided to rip off a man dying of cancer, when even other criminals thought that was a scam too sleazy. His humanity was dead. While that's most stark in the final episodes, we've seen him manipulate others throughout most of the series. He's constantly looking for revenge on Howard, he shows no real remorse when his brother dies, etc. And of course, there's the entire Breaking Bad series, where he's a soulless criminal.
So, he uses all of his selfish talent to get himself a sweetheart of a deal. 7 years in a country club federal prison. And then he hears that Kim has confessed, and that she's taking the fall. Perhaps not criminally, but probably civilly and definitely reputationally.
At that moment, Saul changes. Instead of being selfish, he thinks to Kim. It's not 100% clear if his primary motivation is simply inspiration from Kim -- this good, ethical woman he loves faced the consequences, and he should do the same -- or whether he's trying to shield her from some of the fallout by taking the blame himself. But, symbolically, it's sign of a change. "Saul" becomes "Jimmy" again, as he makes clear by asking to be called Jimmy during his confession. Despite grave personal consequences, he's living his life with integrity for once. He does this not just by owning up to his role with Walter White, but also by admitting to his role in his brother's death and the breakdown of that relationship.
The ending is a reflection on a lot of things. The "time machine" conversation they keep coming back to is the theme of the episode. At first, talking to Mike, he'd use a time machine to become a billionaire. Later, Walter explains that the time machine is really about addressing regrets. Through that lens, we look at the entire life of Jimmy. There are points in time where his path could have potentially been changed. Perhaps if his brother had accepted him more. Perhaps if he had had the confidence to move out from under that brother's shadow. Perhaps if he had followed Kim's example, rather than living his scheming life pretty much unchanged. Maybe if he'd reformed after Howard's death. All of those are potentially regrets, a point when Jimmy could have been redeemed. He's given a final opportunity for redemption, and he finally makes the right moral choice. And thus, despite facing an 87 year prison sentence in a harsh prison environment, he has a "happy" ending, because he's redeemed. (Perhaps there's a biblical reference here, too; Saul of Tarsus has his own redemption story in the Bible, going from a persecutor of Christians to an apostle of Jesus.)
And, with redemption comes winning back Kim's respect. Their love was the one pure feeling that Jimmy had ever had. He loses his freedom, but reconciling with Kim is worth all of that.