The three possible endings for this show. The first two are what I'm hoping for, the third is going to happen.
1) They should just end the show on a cliffhanger. Not something open ended, or up to the audience like Inception (since obviously the show's writers don't trust its viewers with open ended). Just a cliffhanger that has to be resolved, and just isn't. Like we find out Quinn is a murderer, and Batista has been a sex offender the whole time, and Harrison has been kidnapped. End show. The audience trolling would be worth it.
2) I think we can all agree that no one would care in the slightest that it makes no sense. But this whole season can be redeemed if in the last scene, Dexter is shot and the camera pans to...
3) The writers' official ending: Dexter, Hannah, and Harrison move to Argentina, and then Deb can visit them every ten years. Like the ending of POTC 3. The four of them will laugh at some joke, and the show will freeze frame on the group having a laugh and loving life. And the camera will pan over to Harry, who will look at the camera and wink. Then Dexter will narrate "I got a happy ending to my story, because I have people around me who love me." And then Harry will come back to life.