AskMetaFilter has a page which lists their all-time most “Favourited” questions (warning: do not click unless you have a LOT of time to waste!)
Interesting that the most favourited question – “What Book Is The Single Best Introduction To Your Field For The Layperson” – has nearly twice as many favourites (~1141) than the next most favourited question, “What Cooking Secrets Take Your Cooking To The Next Level?” (~614). (In comparison, my most favourited question – “What are some good stand-alone fantasy novels” – surprised the hell out of me by getting 65 favourites…though that makes sense when you think of the geeky/nerdy blend of people that tend to hang out at MetaFilter.)
The third most favourited, “What Childhood Moment Most Contributed To The Person You Are Today” is one I've featured on this blog before – coincidentally when the concept of “Favourites” was first introduced a few years ago.
This post is also timely because the site's now trying an experiment during the month of November to turn off counts on Favourites as it's a long standing debate on the site as to whether this is a useful feature or whether it just encourages people to post funny/snarky comments in an attempt to get lots of favourites rather than constructively contributing to the site.
I'm not a fan of the move (though you can apparently opt out). I know people use Favourites for various reasons – from placing bookmarks as they read long threads to a way to say “me too” without reiterating comments over and over to marking well-thought out posts, even if they don't agree with the sentiment – but ultimately, it's a great way to quickly find comments and threads that, for lack of a better term, resonated with the most people for whatever reason.