Lol I saw versions of this on Reddit, Tumblr and iFunny.
Just some quick rules for the smart-asses who I KNOW will show up.
-No choosing superpowers like “I can choose my own side effects.”
-No choosing super fucked-up side effects like “You have Brain Cancer.”

Mkay! My super power would be to make art exactly how I envision it. A 1:1 replica of my thoughts flowing through my hands onto paper with hardly any effort involved. Lol. :)

Side effect will be that you won't be able to sell it.

My superpower ability to stop time.

Side effect: Everything wouldn't move.

My superpower would be able to blast Water

but it also stops you heartbeat

mind reading

When you read minds, you can't tell if the other person's thoughts are theirs, or your own.

Mass hysteria,the ability to cause a group of people to all feel a certain emotion and act on it like a Hive mind.

Granted but just like bugs you must disperse pheremones into the air limited by range and density of the aromaless effect. With out enough concentration if it the only have a slight inclination to your will. After someone has enough in them it takes about 2 days for their body to get rid of enough to be normal and in control again.

I wish I was designed to be the ultimate medical drone. Capable of synthesizing componds in my own body, and with complex sensors to detect most sickness etc.

Drawback: You can do all that, you were just never programmed with procedures and knowledge of how to treat the sicknesses you detect, requiring an operator.

I'll go simple with my power: an artifact that lets me have powers similar to those of a Green Lantern.

But this will use your life energy. Gradually.

Ability to move through objects.

You're still affected by gravity, so you fall through the ground.

Being able to become completely undetectable at will.

Ah, darn it, I didn't see that. Curse his foresight, I thought I was actually using my brain for once.

(I guess I'll join in!)

Being able to transform into any of my characters at will.

you have prostate cancer (only on tuesdays)

i can turn my left hand's ring finger into a spoon