Elena from TVD, I wish Queen Katherine was the lead

The girl who plays Spencer in Pretty little Liars

DEAD

Screaming

I'd say Harry Potter did progressively get more annoying. Still my favourite series, but I found that I preferred side characters to Harry as the series went on.

Also a kind of random choice but Lord Grantham & Mr Carson from Downton Abbey are annoying at times because they love in such old-fashioned worlds and can't adapt to change well. They're still good people/characters but they can get a bit infuriating.