Rules you, as the title say, limited to one wish.
You can't wish for more wishes. In case you didn't know that would defeat the purpose of me saying lol.
You can't wish for unlimited anything. Like money, or Snickers candy bars(which would be really nice).
You can't wish for things that will affect like a gazillion people. Like world peace. And the wish has to actually affect you.
Oh and don't worry these wishes actually have positive effects not like genie wishes were there is irony involved.
Personally, I wish for a beautiful girlfriend. What's your wish?