Probably doubles with many peoples, in no particular order:
People who feel they need to shout into their cell phones.
People who think England is the name for Great Britain/United Kingdom.
People who tell me they are Scottish because their Great Aunt's cousin owned a West Highland Terrier called Scottie.
F**kin cyclists that think red lights don't apply to them. I say a silent prayer each time I see this, that a mack truck is on its way.
Cigarette butts on the sidewalk (that's fag ends on the pavement for Yhorian, Leud, Graham and Abernyte)
People who don't move to the right on an escalator.
Embololalia: Like when, um people, who like have to like, say like and um stuff, like all the time and stuff when they like talk.
Negative advertising (Buy ours, because theirs sucks. Vote Me because he will tax you and he beats his wife.)
Last but not least - when Discworld or Threshold mud get a head of us on TMS - VOTE you sluggards!