Watching me play City of Villains, my wife has decided that badges need to be awarded in real life. Gamers are willing to go to great lengths for shinies that lack value even in-game, to say nothing of how much it impresses normal people that you got the Keeper of Secrets badge. Gamer spouses, think of how much effort your gamer will put into getting a purely cosmetic “flaming sword” effect, and how you can harness that power for good.
Some people would immediately think of grinding laundry or yard work. Awards at 100, 250, 500, and 1000 garments folded? I would recommend against an award for hours of vacuuming, since you can just turn that thing on and walk away. If I may give away a gamer secret, we already refer to “wife aggro” and think of time with the in-laws as faction grinding (“Just 200 more brownie points to Exalted…”).
My wife, of course, was thinking about sex. You might think that it is sufficiently rewarding already, but can’t we do more? Rewards should be based on quest completion, and grouping will be required (no badges for soloing). This will be a trophy that every gamer will be proud to show off, although there may be questions about RMT.
As WoW has demonstrated, every gamer wants an epic mount.