B'Elanna Torres (Star Trek: Voyager)
B'Elanna Torres is a character whose feeling of ill will goes back years. When we met her she was angry at Starfleet, but over time we also learned about the anger she has towards her father. Specifically, how he abandoned her and her mother when she was younger.
Lilith (Chilling Adventures of Sabrina)
Sometimes anger and ill will comes from being passed over. Like, in the case of Lilith. Lilith was cast out of the garden for wanting to be equals with her husband Adam. She's been "working" towards ruling by fallen angel Lucifer Morningstar's side for centuries, but by the end of Chilling Adventures of Sabrina Part II, Lilith has had enough of his empty promises.
Regina Mills (Once Upon a Time)
Regina Mills's anger towards Snow White is the cornerstone of her character during the early seasons of Once Upon a Time. Resentful that Snow White is the reason her mother killed her one-true-love Daniel, Regina uses that anger to fuel her curse, and all her attempts to control the lives of the Enchanted Forest inhabitants.
John Murphy (The 100)
It's John Murphy against the world on The 100. Shortly after arriving on the ground, Murphy quickly became a dissenting opinion, wanting to sever any connection they had to The Ark. Over the show's six seasons, Murphy has constantly been combative with everyone around him, and it doesn't help that he's constantly blamed and attacked for things he didn't do. (Yea, we still remember how the delinquents turned on him quickly after Wells Jaha was murdered.)
Rachel Duncan (Orphan Black)
None of the Leda clones chose their lives, but Rachel had a unique perspective. She was the only self-aware clone. While Rachel does resent the way she was raised, she also hates that she, like the other Leda clones, is sterile, and she's envious of Sarah Manning and her daughter. Throughout five seasons of Orphan Black, Rachel and Sarah squared off against each other in more ways than one; including putting a pencil in Rachel's eye.
Cersei Lannister (Game of Thrones)
Cersei Lannister can teach a class in holding grudges. She holds a grudge against her twin brother for not coming to her aid in her time of need. She also holds a grudge against her younger brother Tyrion for killing their mother upon his arrival into the world, and for gifting her daughter Myrcella, to Dorne. Definitely sounds like Cersei has more than enough reason to grind some axes.