Horizontal rain which gets all over my glasses even if I'm wearing a brimmed hat (bought specifically to keep rain off my glasses).
Large companies whose call centre workers entirely fail to resolve your issue, in fact make it worse (looking at you, EE; E.ON also a contender here. BT I no longer deal with because they're so shit - but they're linked to EE which may explain things).
Snide sisters-in-law. After 30 years of their shit, I'm done.
People who drive on country lanes but are unable to reverse back to the passing space one car length behind them, and instead expect me to reverse back 50 yards round a bloody bend.
People who talk loudly or play music out loud on trains, buses. People who play music so loudly you can hear it five doors down. People who think screeching in the street at midnight is acceptable behaviour.
Whichever person it is who chucks beer cans into the bushes along the footpath near my house. In fact, any bugger who litters anywhere.
People who let their little darling run amuck and shout the place down in the doctor's surgery, library etc.
Reviewing my (incomplete) list, I see it's mostly people. Not A Fan.