Grammarians that make you cringe:
A while ago I was on a proofreading course (not terribly useful as it turned out) and one of the attendees, who was using the course as an opportunity to plug her firm, mentioned that she had just moved to Folkestone and was standing in the county council elections there. She came across as a bit of a grammar peever, even more than might be expected in the context - she'd love some of this thread! I've just looked her up and she was standing for UKIP. Somehow I'm not surprised.