This takes a bit of thought. If we're talking least favorite because they're written horribly, I'd choose Samantha from The Undercover Spy. That entire book is a mess in my eyes. But, let's try and go with a character who I'd not like if I met them in person.

Obviously my top choice would be all my villains, but I enjoyed writing most of them because writing someone evil is fun. Perhaps my least favorite is Trevor Rossi from Heroes wear Capes. He was created with Lex Luthor from Smallville in mind. He's the kind of person to make wild accusations and assumptions and only believe himself because he thinks he is the most powerful person in the room. I gave him the name Trevor because I knew I would hate him and wanted to give him a name that I thought would suit that hatred.

He's also going to be one of the least redeemable characters. When I write him I sometimes find it hard because he goes against all of my favorite characters. It wasn't his fault he was raised a certain way, but that's still no excuse for his attitude.