Make a Wish. Have it horribly corrupted.

[master1]

Granted, but the world gets boring without the most hatable group of people in it and everyone commits suicide.

Or something.

I wish I knew Aqua Jet. D:

[MOP]

Granted but you lack experience so it always back fires a you.

I wish I had a lovely waistcoat with fine trimming and imported buttons made from ground up rhinos.

[ShinyKecleon]

Granted, but you have to live in an Egg for nine months to learn it.

SNIPED!!!

Granted, but the Rhinos will be seeking revenge at midnight.

I wish that my life wasn't horrible T.T.T.T.T

[MOP]

Granted but your life ends twice as fast.

I wish I could fall asleep now.

[~Evanscence~]

Granted, but when you wake up, you can never fall asleep again, so you spend the rest of your life dead-beat.

I wish I could fly.

[Z:illyhoo]

Granted, but one day you're gonna be flying and a lightning bolt will strike you.

I wish I have better imagination.

[Rorak Kuroda]

Granted, but it only lasts for 45 minutes, so when you are floating above the atlantic ocean on the way to paris, you fall and drown, and if that wasn't bad enough, you see atlantis, but drown before you can tell anyone.

I really thought that one through. And then I was

SNIPED

Granted, but to make up for your large imagination, you now cannot move or talk, so you cannot share your imagination.

I am cruel.

I wish I was a mail man.

[Z:illyhoo]

Granted, but all the dogs in the world will begin chasing you and attacking you.

I wish I had a non-poisoned box of chocolates.

[Rorak Kuroda]

Granted, but you drop them down a well, and go in after them, and get eaten by the well monster.

I wish I was uber pwnage.

[Z:illyhoo]

Granted, but one day, you are gonna meet someone that's uber fail. So fail that you lose your pwnageness for being around that person.

I wish I had no homework.

[MOP]

Granted but now you have exams instead.

I wish I had a pet T-Rex.

[PokeSurfer]

Granted, but it explodes, killing you.

I wish my friend here was more excited about the lazer tag for mah birthday.

[master1]

Granted, but he gets overexcited and ruins your birthday. ;;

I wish Pokesurfer's birthday didn't get ruined (but I had to corrupt the wish somehow). D':

[MOP]

Granted but you corrupted his wish and your wish makes a paradox to destroy you.

I wish I could afford heating.

[Rorak Kuroda]

Granted, but now the weather turns extremely hot and because you already payed for heat, you have no air conditioning. 

I wish that I got to meet Chuck Norris... (again)