I think I'd want Daniel to either end up with Emily or be the one that causes her down fall. I can see him going out like Walter White dying and then in his final moments he reveals that Emily has been poisoned though I reserve this ending for them only if Emily's obsession with revenge turns her into a complete monster and she kills Daniel only to hurt Victoria only to find that Daniel already killed her saying "I already killed you Emily I spiked your wine with ricin."
Though a really good ending is her choosing Daniel and freaking out over the idea he might find out and spending the rest of her day hoping he never learns the truth. Then only for the audience it's hinted that he knows by saying to a stranger something like "Yeah she's beautiful I met her years ago outside of the Hamptoms though I didn't remember where til just recently." I like that idea because they did meet years ago in a flash back but Emily was spying on him and in disguiss.