I love villain's and the bad guys in movies or series. They usually can be way more complex and intresting.
One of my favorite character you love to hate is Dan Scott. He is the kind of father who can't let go of his past, left his high school love while she was pregnant and never cared to show intrested, got another one pregnant and put the worst pressure on his other son, manipulate people alot, got an intense relationship with his older brother and kills him at the end and much more. He did alot of bad shit but later on towards the end of One Tree Hill, he shows a different side to him.