Hmm... I never thought about the desirability of a standardized "I loved it". As delicious amply demonstrates, the fact that someone else liked (or loved) something doesn't mean it's even remotely well-written. Oftentimes it's bad, sometimes completely unreadable. Once you reach the point of looking into a particular fan's bookmarks, then you can start forming an idea of their taste and then the loved-it tag becomes more potentially useful, from my point of view.

I never browse by "first-time" in other people's bookmarks, but I do tag for "established relationship" and "preslash", which I suppose (mostly) creates a first-time category by process of elimination... it has been the standard story type for such a long time that I suppose when I started bookmarking it seemed like a waste of keystrokes.