One such peeve is when a developer "signs" their change with their name and the issue number. The information is already in the commit message and if I care then I'll annotate and log it. These "signed" comments quickly become outdated and even misleading.
Another peeve is a lack of whitespace between statements, clauses, and parameters. A lack of sufficient whitespace only hurts the programmer when they have to modify the code again.
Smashing elements together on the same line as other elements or the specifier (e.g. array(long ele, long ele)) with no new lines between each element (e.g. array(\nlong ele,\nlong ele,\n)). It's especially annoying if they do some mix of new lines or same line, like the first n or last \n missing. Don't get me started on the middle one missing.
There are others of varying degrees of annoyance.