The rules are pretty simple, someone makes a wish, but you have to grant it and give it a bad unwanted side effect, then you make a wish.
I'll start.
I wish for world peace.

I grant your wish. *everyone turn into zombies* :)

Now you gotta make wish :D

I wish that instead of rain, there were oranges :D

Granted. You are now permanently allergic to oranges. Also the ecosystem is screwed.

I wish for Neural Virtual Reality.