My first thought is that you're doing it wrong.
What's writing out that list of links? Are you looping through an array or something and writing a link for each item? If so, then the logic that strips the final slash off should surely be happening there, rather than writing it all out and then writing some additional code to amend the output once it's arrived on the page.
If that's not the case, then...
You need some <li> tags around your <a> tags. ie:
<li><a href="animation">animation</a> /</li>
<li><a href="2-D">2-D</a> /</li>
with that HTML, you could strip the final slash off the final list item with:
var lastItemHTML = $('#tags li:last').html();