This example isn't perfect due to the fact XenForo offers a solution to combat this particular instance but take a look at the suggestion board: there's 4,268 suggestions (assuming that each 'discussion' is in fact a suggestion). There could be some quality suggestions in there, and there's probably several duplicates, but it has 54 pages. Nobody is going through all 54 pages. The feature I was referring to combat this is the ability to sort nodes threads by likes instead of last post, which they actually do here but that still requires people liking the first post.
What I'm proposing is an add-on (that I will be developing soon, ad manager is still my highest priority), that will display a new sub menu under Forums called "Top Content". This will have searchable content, where you select threads or posts (default options, I'm going to make it semi-easy (no coding will be required) to add more content types such as blogs, gallery items, etc) along with which node you want to view. Then I'll return a list (or the actual post layout, depending on options set) of the highest quality results.
The quality score will be determined with a formula that I'm not entirely sure of at the moment. I plan to take into account the posts age (as it's still relevant), the # of likes received, the # of views and replies (only applicable to threads).
I imagine it'll look something like this:
(5*likes) + (50 * (replies / views)) - (daysOld/4)
so a thread with 5 likes, 100 views, and 1 reply that was made yesterday would receive a score of:
25 + 50(1/100) - .25 = 25.25
I need help deciding how important each aspect is. The actual score won't ever be seen so it doesn't really matter how big of a number we end up working with.