Okay so I will start.
I used a Wild Die in my game, much like the old WEG one, expect on a 1 the players has a choice, lose the highest die or get a complication in the scene. On a 6 they have a choice as well, explode the die (which keeps exploding on 6s) or get a Perk in the scene.
It worked rather well for us and lead to some excellent and exciting moments!
"The English language is the product of Norman invaders attempting to pick up Anglo-Saxon women. The resulting language is about as legitimate as the resulting offspring." — From the Internet