I read it front to back, beginning to end, all the time. But I have a few memorable moments with one being controversial with others because of how I think of it.
My top moment that comes to mind is the return of Michael. Not only the sacrifice he is about to make in SG only to get Uriels grace and kick out the gate and begin to throw down with Nic, but when Harry shows up earlier and says "I think I'm lost."
Another is at the end of SmF in the hospital and Charity telling Harry that family stays, confirming that Harry is part of her and Michael's family, blood or not.
The last is the controversial one. It's the death of Murphy. Some find the whole scene, killing the giant to the lights going out, as a worthy but pointless death. Some find it as Jim killing the series (to which I say, give it time, he already killed the main character and he came back). But I am one who is actually happy that she is gone. Before you get out the tar and feathers and the torches and pitchforks, hear me out. The character of Murphy needed a break. We the reader had her in every single book since book one. The only break we got from her was DB. And ever since BR, when she took the deal with Lara, she has been going down a darker path. It was only since Aftermath that we really noticed the change.
So now that Murphy has died we can see her heal. She can find herself again and not be the hurt, lost person trying to play in the big leagues, only to get more hurt and more lost. We can see her again near the end being better than she ever was before. That's why I think it memorable, the loss of the damaged, broken weapon (body) only to come back stronger and better. And we get a break from a character that was grinding people's fears a bit the past few books.