Re: makeup pet peeves....
Smudges of any kind. That's why I don't even use pencil/cream/gel/liquid eyeliners because they will always smudge. And it has taken me literally years to find a mascara that doesn't smudge at all.
As for pet peeves on other people, I'd say super thick black liner (i.e. WAY past the fold and up into the crease, a solid black half-moon). Um, could you please blend that out so at least it looks like shadow (not that black shadow up to your crease is necessarily flattering)? Because right now you look like you got punched in the eye, srsly.