Bigots.
People who think its ok to tell you how to live your life - and try to force you to change or convert you to their way of thinking/lifestyle/religion. (see bigots, and add Jehovah's Witnesses, soapbox preachers, most conservatives in general but particularly politicians and commentators, small-minded neighbours, clerics, meddling Labour politicians, social workers, advertisers... the list goes on)
Chavs.
Squealing kids voices, particularly in South of England accents - sets my teeth on edge.
Snobbery.
People who can't drive, but insist on doing so.
Being talked down to or manipulated.
The Daily Mail - reactionary, little Englander, petty, self-righteous, hate-filled, sensationalist drivel dressed up as common sense and decency.
The British National Party and their supporters. Someone please round up these s**theads and exile them to St. Helena.
That'll do for now, before I turn into Victor Meldrew...
Dunc