You can choose a superpower, but the first person to reply can choose a side effect... Go:

I'll be the first !!! so the side effect would be that water can only be in its liquid form when you are near... No more iced coffee or steam baths buahahah 😈

My superpower would be to be able to overcome weight. So, gravity. So, I'll be able to jump on top of tree tops, fly, walk on water, but also go to space and not get carried away