We automatically assume Glenn because in the comics, this is Glenn's final death scene. But the show has made it very clear that it doesn't follow the comics entirely. For example, Denise's death scene was actually Abraham's death scene so with that being said killing Glenn off here is a little too obvious. We can also eliminate Maggie because it is clear to Negan that she might already be dying, so there would be no point in killing her off now. We can expect that if Glenn or Maggie were to be killed, that it will happen in the next season.
Killing off any of the minor characters such as Sasha, Aaron, Eugene, and Rosita can also be eliminated because they were all recently introduced and being undeveloped, it will seem harsh to end them immediately. Their deaths will not have a significant impact as opposed to the other characters. Negan eliminated Rick and Carl when he states "Anybody move, anybody says anything, cut the boy's other eye out and feed it to his father", so both of them are also unlikely.
So that leaves us with Michonne, Daryl, and Abraham. All of these are valuable options to consider. If Negan decided to kill any of them, Abraham's death will have the least impact, so that leaves me with thinking that Negan kills either Michonne or Daryl and I finally conclude that it is Michonne, here's why:
In the beginning of "Last Day on Earth," the episode begins in first person. Coincidentally the episode ends with the same person's point of view, that being the person who is brutally killed by Negan. We don't know whose point of view it is until it is later revealed in the episode as being one of the people in the van. Those people were Rosita, Michonne, Glenn, and Daryl. We already eliminated Rosita and Glenn so that leaves us with Michonne or Daryl.
When the van is opened we can clearly see that Daryl's head is in the bottom left corner of the first person. So I automatically eliminated Daryl as Negan's victim. We are seeing through Michonne's eyes because when is the one sitting directly behind Daryl. Also during the Eenie, Meenie, Miney, Moe game we didn't see the bat pointed in her face at all so I concluded that when it is finally pointed at Michonne, we are seeing it from her point of view, confirming that she is the one whose eyes we are seeing this through.
Michonne is one of my favorite characters in the The Waking Dead. I can't wait to confirm my argument or learn that Frank Daraont had something else planned for Michonne. I hope to see her next season but the clues I gathered from the show ultimately confirm her demise, ending her as a major character in The Walking Dead.
