Obviously this is quite a limited choice, but I have to go with Dudley Dursley.
I know what you’re thinking. The spoiled, wretched little bully who tortured Harry for a lot of his younger years, how can he possibly be your favourite, Al? What are you thinking?
I think there’s a lot to be said in the defence of Dudley Dursley. Firstly, he’s a product of his environment – two horrid parents who despise their nephew – he wasn’t ever going to be warm and loving towards Harry, was he? Dudley is spoiled, his parents spoiled him and treated him like God’s gift and so he was going to act it.
But Dudley does grow up in some senses. Though we don’t see a lot of it, in the final book (and deleted scenes of 7part1) Dudley is actually grateful to Harry. It’s almost sweet.
Yes, he was a nasty little bully, and part of the reason we hate the Dursleys as a whole, but Dudley can’t be entirely blamed for that. There’s a much deeper reason to how he’s turned into who he is.
Dudley, you’re not all bad, son.