1) Patronizing people who tell you how to do your job and what you should be writing about, with completely no understanding of how a newspaper or its readership (apart from their individual selves) works.
2) People from the finance sector who have forgotten how to speak to real people. So everything is stated in terms of the bottom-line imperative (which was the big problem I had working for a finance publication, where I was supposed to admiring of initiatives that made money without any consideration of the human cost) and couched in some cute management mantra which means absolutely nothing in actuality.
3) Government officials or staff from large mainland corporates – a follow on of speaking in mindless management jargon. Except unlike the earlier category, the responsese are predicated by the need to use as many three-syllable words as possible regardless of meaning. There is also a propensity to read from a sheet of previously sanctioned responses and to answer any possible question with whatever the planned answer was regardless of its relevance to said question. (I realise I am beginning to write a bit like that but I hope I am making more sense).
4) People whose agendas are so out of line with your own but to whom you have to nod and make some sense of their inexplicable bigotry simply because you know an argument is not going to change their views and you need to get a quote and be out of there. Could overlap with any of the above categories.