I like the CSS only solutions. Very often I need to select a specific DOM element. Sure I could add a new class, but it is always nice if I can do that inside my stylesheets. It just looks better and keeps my HTML markup clean. first-child, last-child and nth-child are made exactly for this purpose.

Checkout Revealing the magic: How to properly convert HTML string to a DOM element article.

I'm working on a chrome extension which accepts user text, work with it and output the result in a div. I used jQuery in the beginning, for several tasks, but later I decided to remove it and deal with pure javascript/DOM manipulations. The output div was filled by using innerHTML property and everything was ok. But, at some point, I sent few buttons to the user and he has to interact with them. However, once I update the div's content the event listeners are detached and the buttons became non-functional.