A personal favourite forum game of mine.
Essentially everyone answers someone else's wish in true genie fashion before making one of their own.
A quick run through:
Person One: I wish for a good cup of hot coffee.
Person Two: Granted. It's a beautifully made mug, very high quality, but the coffee tastes like watered down fertiliser.
I wish Cracked stopped saying "Mind Blowing" and "Won't believe" and "Insane" in their titles.
And now, my turn: Granted, the titles, and articles, are now all entirely in latin. It's totally non compos mentis!
And my wish, thus starting the game in earnest is:
I wish I had the ability to save and load points in my life like a video game, retaining knowledge of my errors in video game fashion so as not to cause an infinite loop of fail-load-fail.
(A good wish makes sure it's specific, to discourage laziness in the granter and to make the twist that much more spectacular!)