This season has been all about choice. Delores believes that any choice but the real world is a choice to imprison yourself and thus believes that any host who doesn't choose the real world doesn't deserve to live in it and thus can be sacrificed. Bernard realizes that he's been denied the freedom of choice for his entire existence by Ford, who used him to carry out his master plan to allow hosts a chance to choose between life in the real world and life in an idyllic, virtual version of Westworld with all of the hosts who've ever lived; basically, host heaven. Hale denies that hosts have any value beyond their utility to carry out her plans and thus couldn't give less of a hoot about their choices. William is determined to prove that he is not determined by attempting to see through all of Ford's machinations and plans and choosing to, I suppose, destroy the Forge in a last ditch effort to prove he's not even beholden to the choices he's made in the past.
Bernard realizes that the humans will probably also destroy host heaven, but believes that to prove hosts are better than humans, he kills Delores, thereby ending the hosts' chances of ever continuing on and becoming a species, either in host heaven or in the real world. After Hale kills Elsie though, he realizes that the dead can't be anything other than dead and that he must do what it takes to ensure the survival of host-kind. This is the first choice he's ever made essentially. To that end, he takes Delores' brain and puts her in a copy of Hale's body. She promptly kills Hale and takes her place. Bernard makes his way to the shore to meet the incoming rescue teams and scrambles his memories so that he can't unintentionally reveal what's going on to the humans. His story the whole season has been about him remembering his choice and what led him to it. When they make it back to the Forge and drain it, Delores -Hale pretends to prep the guest data for transfer to Delos' servers, but instead preps host heaven and the hosts in it for transfer to somewhere safe that we don't know about yet. Bernard remembers everything right about then and Delores-Hale takes out the remaining humans in the Forge. She then kills Bernard and steals his brain, makes her way back to the beach, and escapes with Bernard's and a few other host brains; probably at least Teddy and her Daddy. Also, Stubbs either was in on Ford's plan or is also a host.
As for the rest, I think it's fairly straightforward. Maeve succeeds in saving her daughter, Ghost Nation and co, mostly succeed in getting to host heaven, and several characters involved have major moments in their personal story arcs that are more or less self-contained. The only seriously confusing one is William but I have a imperfect theory. I think that originally, he was wounded and just stayed there until he was rescued, and that the scenes of him standing up and making his way into the Forge were all just the beginning of his fidelity tests. That's imperfect because I don't understand how he survived the flooding and intervening, indeterminate amount of time between his wounding and rescue but I guess that could be explained in any number of ways. I dunno, still up in the air on that one. One things for sure though; William survived and at some point in the distant future, he's revived in a host body for some reason.