People who clip their nails in public.
You guys remember the carpet guy from my job? I will post if you don't. Anyhow he has to be the worlds biggest freaking slob. In addition to clipping his nails at his desk with no pail, in the open, he shaves at his desk with both electric razor and Mach five.
However, yesterday he did something so horribly disgusting and vile I wanted to kill him. He jabbed a mustache clipper in each nostril and clipped his nose hair at his desk. When he was done he jams his finger in each nostril and swirls it around like he was digging for gold. I was so skeeved out, I wanted to hurl.