Eugene is too important to how the story develops, but then so was Andrea...
I agree that Darryl is the most likely, but he's so popular...
Glen should get the honor -- he earned it,
and it would be extra horrible, given that Maggie is there.
I endured a few minutes of the Chris Hardwick Licks AMC and Kirkman's Balls Show, and they had the gall to claim that this wasn't just a "cheap stunt", and that the pay off next season would be worth it.
No, it most certainly is a cheap stunt, and they are writing IOU's their production team rarely makes good on.
I'll hang in to see Negan -- although I usually don't like their deviations from the comic (and not because "canon" , but rather just not better writing), I
did like their take on the Governor... well, other than them really toning it down in regard to his various interactions with Michonne, but I certainly understand why they couldn't go there.
So, their version of Negan
might turn out to have been worth the wait...
We'll see, I guess...