I agree with Jon about not needing an ID if you are linking to the top of the page, but I disagree with his statement that it is "poor coding" to use <br/>. There are two different purposes for the <br/> (go to the next line) and the <p> (start a new paragraph element). Technically (semantically) you aren't starting a new paragraph with each line of a TOC so a <br/> (or a <div> for that matter) would work fine. Effectively they will do mostly the same thing under most conditions, but they are semantically different. Honestly, if there isn't a specific reason for using one or the other, it's a matter of preference for which one you use.
I personally use the <p> tags... but that's just a habit instead of any particular reason.
Cheers,