Some notes:
- The two guys in hats at the end were IRS Agents. In real-life Nucky Johnson was investigated and eventually arrested by IRS agents in the 1930s. So even if Nuck didn't meet his ultimate fate, he still would've had to deal with other ramifcations.
- The Commission. Great closure or to be more pertinent, the beginning of their regime.
- The scene with Capone and his son. Them emotions, man.
- Margaret winning and flourishing. Gotta give her props for evolving and transforming into a power and independent woman. That line, "Think of all the things you want out of life. Now imagine yourself wearing a dress" could not have been a better way to sum up her life aspiration both personal and business.
- Commodore and creepy sideburns Leander.
- Narcisse's death was brutal and quick. Glad the dude got his. Remember that play production he directed last season?
He was his only and biggest fan.
- Poor Gillian got her "sickness" removed by Dr. Cotton experimental procedures. :x Even if Nuck had read the letter earlier, he still wouldn't have helped her and thus continued to break his promise of protecting her. No redemption from Nucky.
- Joel Harper. When he uttered the words "Mima" I literally dropped my jaw. It was predictable but yet unpredictable in a counter-intuitive sense that I had anticipated that couldn't possibly transpire but then it did and caught me off guard. He also shot Nucky right where Nucky shot Jimmy in the face too. Also, when those college kids wearing the P sweaters appeared, I immediately thought of Princeton and how it alludes to Jimmy Darmody's alma mater.
- Richard Harrow would be vastly disappointed. All that he did for Tommy went out the window and straight to prison.
- In Nuck's final encounter with his little brother, he mentions he swam further than he did. Also when he says to Margaret with the line of wanting more - a penny to a nickel to quarter. In the final shot of him finally catching that coin symbolizes that growing up poor caused his ambition to get best of him but everything else drowned including him, his wife and people he cared about. If he would have caught the coin in the beginning, his life path may have been different.