FAB Five Faves

You get that badge if you click "Add to Favorites" for 5 games in the Arcade. It appears just below the game itself, next to the stars for "Rate this game" — by the way, you can also get a "Arcade Raves" badge for Rating a Game, 

There’s an old thread about arcade badges.  To find it, go to the Arcade Forums page, on the left below "Most Smiled Authors" is a section called "Top Tags."  Look for the tag named "badges" and click on it. It will come up with a list of posts in a thread called "What Kind of Badges can you Earn?" Click on any of those and it will take to the thread where lots of the Arcade badges are explained.

Ryan, what do you do to get it?

ballet412, it means Fabulous Five Favorites.