This took me some time… I thought of some characters that really agitated me. People like Koga, Kagome, and Jaken from Inuyasha. Su from Shugo Chara. But none of these characters compare to the tragedy that is Excalibur from Soul Eater. His rules, his obnoxiousness, his mandatory 5 hour story telling parties, his voice. There is no challenge when it comes to the most annoying character ever.