Ok I was thinking that you can put a little icon next to each thread depending on how popular it is.

For example:

A thread with only a few posts will have like a mini AG symbol next to it.

Then when it gets a certain number(50 or 100 posts?) it will have a new icon like a different symbol and it represents that it's popular. maybe like put flames behind the sheild to show that it's hot.

If a Moderator posts it it can have a golden shield instead.

I feel it can let people know what a lot of people post on.