Well, there's a two-tiered response to this. In terms of antagonist hate there are two ways to hate them:
Poorly designed antagonists - Hate them not because they are dastardly or because the epitomise the lowest actions of humanity, but because they're just bland, or stupid, or arrogant. In this category my vote goes to:
The other way is the compelling villain. The one who's actions make you hate them and want to bring them down. Despite its lightness of tone, the Phoenix Wright series managed quite a few of these absolute bastards. But I gotta say my favourite out of the bunch was:
There are a lot of good villains out there though, and it is possible I've forgotten some. The Joker gets an honourable mention for some of his incarnations (Heath Ledger and Mark Hamill are particular highlights for me).
Poorly designed antagonists - Hate them not because they are dastardly or because the epitomise the lowest actions of humanity, but because they're just bland, or stupid, or arrogant. In this category my vote goes to:
FF7's Sephiroth. He just a complete non-entity. Swaggering about with nihilism dripping out of every pore. That in itself isn't so bad as there are so many poor excuses for antagonists. He gets a special mention because despite being a terrible villain, he's often hailed as the pinnacle of villainy. So many times when people discuss their favourite villains, he always makes an appearance. And I honestly cannot fathom why. Purely based on his design seems to be the big reason, but he's a platinum haired androgene with a sword bigger than him in a world almost exclusively populated by platinum haired androgenes with swords too big for them.
The other way is the compelling villain. The one who's actions make you hate them and want to bring them down. Despite its lightness of tone, the Phoenix Wright series managed quite a few of these absolute bastards. But I gotta say my favourite out of the bunch was:
Dahlia Hawthorne. My god I wanted to end her so badly. A manipulator of the highest calibre, a monster with a pretty pink umbrella, and utterly no remorse. I honestly cannot remember wanting to bring about a villain's downfall more than hers.
There are a lot of good villains out there though, and it is possible I've forgotten some. The Joker gets an honourable mention for some of his incarnations (Heath Ledger and Mark Hamill are particular highlights for me).