I'm not really the type of person that hates but there are some characters that I could do without in books.
2. Written in Red by Anne Bishop. The main villain was the Controller, who is trying to get Meg back because her skin is worth a lot of money (basically a slaver), but I hated Asia Crane. Bishop wrote from her POV every so often showing her plotting to hurt Meg, and all of it was just for a stupid acting career, such a shallow reason!
3. Legend by Marie Lu. Commander Jameson, she was one of the main villains of the three books and like a lot of other people I just hated her so much. She used June and ordered soldiers to kill innocent people.
4. The Harry Potter Series. I hated Bellatrix for a big reason that I'm going to spoil.
5. Fruits Basket. My first ever Manga series, and the character I hated was Akito, the head of the family who is both creepy and ruthless.