What is your least favorite kind of person?

Like, the kind of person you just cringe away from immediately? For me it would be those self-important atheist peeps. Y'know, the people who seem to think they're the next Albert Einstein, who twitches in their seats whenever someone says something about religion, and most definitely got a fedora in their soul. I'm not religious, but holy hell, those people are the most annoying people out there.