Something that really annoys me is when people abuse the lax semicolon rules in JavaScript. Personally I believe semicolons should be a standard and always used in a language like JavaScript, and while the loose rule on semicolons may be considered convenient when one is forgotten every now and then, it is /not/ meant to be abused and semicolons completely unused. It's particularly annoying when I have to work on a group repo at work and the standard is to not use semicolons. JavaScript to me is much more similar to a C style language than something like Python, so even though the language is built to be loose and easy conventions such as bracket scoping and semicolons should be kept and practiced.