1. A significant and permanent increase in goodwill globally, which would affect all nations equally. After watching a certain episode of X-Files, I would not dare to wish for world peace.
2. Everyone would believe everything I say. The second option would be that everyone would always obey me, but I think this one is even better. The universal and unconditional belief in my every word would enable me to get whatever I want.
3. I would like to live a fully healthy life without any sickness or abnormal pain until I die. Getting old and sick frightens me, death itself doesn't. This wish could get a bit weird in some cases, such as of I got into a car accident and I'd receive fatal wounds that would kill me within minutes. In this case, how could I live a healthy life until I die? This wish could easily fail. A better wording would be required.