I hate the sound of crunching when people eat. It's so grating. When people crunch on potato chips, apples, carrots, whatever. I especially hate when they exaggerate that sound in commercials. Ugh.
I think that's probably a good indicator of when it's time to get out of a relationship, actually. If you look over at the person you sleep next to most nights, and the sight/sound of them crunching on some edible makes you wish death upon them, even though they're doing absolutely nothing wrong, just sittin' there tryin' to enjoy a late-night snack in their PJ's, can't really control the volume of the crunch that much...it's probably time to move on.