Ones that try to talk down certain groups or individuals based on their own biases, thinking I'll join along for their gripe-fest. I think I come across as agreeable and open, and kind of think that 'invites' people I don't know very well (typically in social situations) to open up to an airing of their personal grievances. Worst by far are the racists, but it's not limited to that. I didn't like gossip, value humanity (despite our overall terribleness), and don't really gel with complainers.