My coworker's incessant noise. I swear he's a one man band, it's unbelievable. If he isn't speaking to someone, he's talking to himself. If he's not talking to himself, he's humming or singing to himself. If not that, he's playing the drum on his desk, or flipping random objects and dropping them. If not that, he's stomping his feet, if not that, he's slurping his cup of tea. I was mere moments away from screaming at him to calm tf down today, it got on my nerves so bad that I had to leave my desk and wander around to calm
myself down.