I already know my answer.

Draco while he hated Harry respected him. Hermione meanwhile was muggle born and Ron was what Draco considered a blood traitor which was considered by some worse than muggle borns so Harry is hated the least.

I think he hates Ron or Harry the least. He def hates hermione the most though "As for me, I hope it's Granger"

 "As for me, I hope it's Granger"

That was only in the Chamber in Secrets, I think Ron and Harry are on top of Hermione in Draco's hate list.

At least Draco didn't ACTUALLY try to kill Hermione (he did try to kill Harry though)

^And he carried on displaying hostility to her throughout the series. Harry was his nemesis and constantly interfered in Draco's plans making aggressive behaviour towards Harry by Draco more likely.