What got me most about the ending...[spoilers]
...was the parallel drawn between the first meeting of Clem and Lee and their goodbye.
Clem was crawling away from the security guard walker and I had to shove a weapon towards her. She grabbed for it, turned to the walker, and bashed its head in. And then did it again. And again and again, as Lee watched on. Then the bird's-eye view camera angle, with Clem poised over the corpse with Lee in the background, and it hit me: it was the first meeting at her house, all over again. Only with the roles switched.
I don't know why, but that simple thing made the goodbye even harder for me. I guess it really just drove home how much we've been through together, and how much stronger Clem's gotten since then. It gave me a lot of closure I'm not sure I would've gotten otherwise.
Hell of a ride, TTG. Looking forward to the next one.