Corrupt a wish! Credit to people who did this before me!

[the golden god]

granted, but you can never, ever spend it.

i wish for ten thousand wishes

[sir stingray.]

Granted, but they can't be used for yourself

I wish I had a kitten

[Sapphire_Amulet]

Granted but it really hates you

I wish for a potato

[sir stingray.]

Granted, but it can't be eaten or cuddled with

I wish I could live fforever

[Demon God Caelan]

Granted, but you have to live on the moon

I wish Nintendo would lift my 3DS's internet ban

[TheSongOfTheStars]

Granted, but it's erased all your games and the progress you made on them

I wish for this wish to be corrupted

[threezeum]

granted, your wish now does nothing

i wish i was skinny

[zenisiti]

granted, but now you'll have bones sticking out weirdly
I wish I could fly

[cKy]

granted, but only for three minutes at a time and it anyone sees you you die
i wish to see my chemical romance live in concert

[Ɽotten Ⱡegacy]

Granted, but it's outside, and it turns out to be so cold at the concert that you have to leave before you have a chance to see them play.
totally not from personal experience

I wish I could confirm whether the Wessex Way monster is real or fake--and if it's real, what exactly it is.