The show would get crucified if they killed Darryl off, but it would make so much sense for future relationships and episodes, since Abraham is has been introduced. That's not going to happen.
I'm tired of the Glenn/Maggie thing. I like looking at Maggie, but Glenn is a useless character now a days. If Beth is dead and the they follow the comics, it could be Maggie.
A death who would shock a lot of people, would be Michonne. She has become popular. It would be a shocking way to end a popular character.
Rick and Carl are not going anywhere. It's their show.
I will go with Michonne.