Here you go

I wish that I'm not busy.

You're not that busy anymore. You have too much time on your hands. You create a rocket that accidentally self destructed and blew up the Earth. Good news is, you're on the moon now that the explosion blasted you there and you're not busy anymore.

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I wish I knew what to wish for.

Edit: Wow my wishes are that hard to corrupt? O.o

But, your thoughts are erased immediately by something that we do not know about.

I wish to have a 15 kilovolt shockdevice using a flybacktransformer from a crt television

Granted. You electrocute yourself.

I wish for a small fusor, which is capable of performing nuclear fusion.

You do get a small fusor and you can generate massive amounts of energy without you paying for it but then the Illuminati sends soldiers to your house, shoot you to death and destroy the fusor, burying it in deep in the Earth.

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I wish that my dream civilisation was real and the Illuminati was defeated forever (read profile bio :P)

Yep, it's now real and the Illuminati was defeated-

Oh, wait, a nearby volcano erupted.

And here comes a tsunami.

And an earthquake.

Oh, I see about 20 tornados on the horizon.

And WEATHER-E satellite detected 5 Hurricanes diverging onto your country.

Oh, I see some of the Illuminati's followers headed to burn down your country.

Good luck :P

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I wish for a brain.

You get a free Candy Cane. Then you eat it. Then you want another one. You eat it. You get fat. You die. The end.

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I wish I had a real working prototype of WankerYager 1.

Granted. You are shot in the head with it by a home intruder. They leave it with you as your dying wish.

I wish I understood c++