I've always wondered about a single line on it's own. Sometimes I use a caption, but I default to <p> for not coming up with anything more appropriate. :-) So what would be "perfect" for a one-liner?
At any rate my solution to avoid the empty <br>: I usually style the element with padding or margins or width so that the content area narrows enough to force line breaks. Unfortunately they don't always break where you want them to, but it's one less hard coded element.