I would love to be a good singer or a good football (soccer for americans) player, because here in Europe football moves mountains of people.
People cheering for my name on stadiums and the honor of representing my country on a world cup would be something I would really appreciate, it would give me an unexplainable feeling of joy.
And singing because I love music and I would love to carry my emotions to other people, someone like Bruno Mars or Michael Jackson (I won't discuss tastes, we are free to like whoever we do). The people that go through X-Factor, Britain's Got Talent and others (those who really know how to sing) make people feel good, and that feeling of having people to like you and to cheer for you is amazing, because they like you for something you do.
And what about you? If you could be really good at something, what would it be?