I'll start with dirty bastards sat opposite me in libraries or behind me on buses chewing their gum so bastarding loud that I can hear every squelch. Eurgh.
People playing music without earphones on public transport
People playing music through earphones on public transport so loud that I can hear. It no longer becomes a personal ipod or mp3 player because my ears can hear the damn tuneless drones of the tasteless music.
Spitting. Just eurgh.