Kids in restaurants that cannot behave. If you have a hyperactive little gobshite, take them to wacky warehouse.
Also, regarding above, parents who give their brats an ipad when they go out so they can sit there like zoned out mini zombies while Mummy and Daddy can sip on their Sauvingnon Blanc undisturbed. Here's a thought, how about actually interacting with your kids rather than giving them a digital babysitter. Or, just get a babysitter.
OTT makeup, particularly eyebrows like fat slugs.
Milk / ice cream
Moths / butterflies, basically anything flappy
Most fish, I'm ok with the likes of cod but any fishy fish is disgusting.
People that post every goddamn meal they make on facebook, like they are the only people in the world who can cook.
People that wear so much perfume or aftershave that I can literally taste it.
Teenagers that do a false swagger type walk to try and look hard. You don't look hard mate, you just look like an utter knob.