You could put a great big red arrow on the active convos list against the likely contenders. It's not always easy to tell a bunfight from a long-running chatty thread, so number of posts isn't an infallible way to find them.
Failing that, can we have a bun emoticon? The cake and biscuits just aren't precise enough.
I think we also need a tongue-in-cheek emoticon, while I'm on the subject. 