It was hard trying to avoid spoilers on twitter all week until the UK screening.
What an amazing ending! I admire how brave it was to basically take the main character completely out of his usual setting for the last couple of episodes. And you never see him go back. What other show ends with your protagonist only interacting with the other leading characters over the phone? And how superb were those phone calls? Don called the three most important women in his life: Sally, Betty and Peggy. I found those scenes to be highly emotional, particularly the Betty call, like you guys said.
I was wondering if they were gonna do something with Coke at the end. There were kinda portents leading up, like in the last episode where the motel owner asked Don to fix his Coke machine. But the way Matthew Weiner did it was so clever. And to have the girl at the commune have her hair the same way as the girls in the ad - a wonderful touch.
I will miss this show sooooo much. I could happily watch an Olsen-Harris spin-off but they didn't play it out that way.
The show had ups and downs over its run, but I think way more ups than downs. I recently watched a few of the earlier episodes again. I would probably sit down and watch the whole thing again from the start if my real-life responsibilities didn't get in the way!