Well, it would take me hours to list everything I would wish for, and absolutely none of it would be for me, but ...
My main wish would be for every single human being on this planet to stop killing others when there is absolutely no valid reason for it. 
My secondary wish would be that the entire world get rid of its dependency on fossil fuels and anything that produces harmful waste or gases that are destroying this planet. We need to develop more in the way of solar and other alternative power/transportation sources if this planet is to survive.
My list would go on and on ...
EDIT: Actually there is one thing I'd like. I'd like a billion dollars so that I could give it away to those in need. I already do that now when I can, but being able to do it whenever the need was there would be absolutely fantastic! 
