I will not spend time delivering an all-out think piece on the subject. That has been tackled plenty here, here, and here.
Many of my thoughts on the finale, and a series as a whole, has been said in those links. Well, bits and pieces from each one, that is.
I thought the episode was everything I expected and more. Before the episode began, I desperately wanted my prediction of Don Draper (Jon Hamm) returning home to his family, leaving us with a final shot of him looking at his kids and smiling, to come true, it was clear pretty early in the episode that it wasn't going to happen that way. And I'm glad the episode took the route it did.
Over the years, we have seen Don bottom out and find a new solace in life (i.e. swimming, writing in a journal, sobriety, a family man), only to fall further into the abyss than the time before. This final season put him through the wringer one final time. There was a finality in people pulling away from Don. His inability to control and fix problems in his own life led to him running away and falling deeper into the abyss. The final shot leaves me to believe he finally came out the other end finding the peace he needs in life. And I do believe he got his job at McCann-Erickson back and helped create this iconic Coke ad.
An ad that truly was created by a man at McCann Erickson.
The reasons I see Don finally digging out of his eternal abyss is because of what occurred in Don's previous scene. To me, that is the scene that reaffirms my belief that Don came out of this experience a changed man, fully shedding the evil and loneliness that he was cloaked in for all this years. For the first time in his life, he was able to fully give love and not just receive it. That moment he gives a hug to the other man at the retreat is everything I wanted from Don and more. This scene, in addition to the last line with Don chanting "Om" on the cliff, provided a series finale that ended with a bit of hope. In a finale that was filled with characters moving forward in their lives and/or careers, this is the first time I ever felt Don was truly moving forward and possible creating a positive chapter in a life fraught with booze, cigarettes, women, and bad decisions.
A hug. A smile. A coke. Brilliance.