For a fun wish, I'd like to be Peyton Manning. A great QB and a heckuva good guy with a sense of humor.
For solving the problems of the world, I'd like to be President of the US. Instead of being in the pay of the megacorps, I'd be able to do what's right for everyone.
If it was a job, the wish would be to have the CEO position for GM. I'd like to restore domestic vehicles back to their former prominence.
For fame, being a rock star in the days when rock held sway was the Best Gig Of All! Being the rockstar who brought back rock to the fore would be a great wish in my book.
In historical signifigance, the biggest thing I could wish for would be to be the first person to contact intelligent alien life.
Rick