Your choice of college, whether or not you will marry, whether or not you marry the right person, the decision to have children or just have dogs, the decision to resign from a job and move to another city or another state to take another job. The decision to join the military, or to attend a family reunion when you haven't spoken to your mom in years. The decision to stop smoking, or drinking, or doing drugs. The decision to turn in someone you know is doing something harmful to him/herself or others.
The list goes on and on, and it will not be the same for every person who answers your question.
I take it this is an essay prompt. The answer to this is going to be different for each person. These types of essay prompts can be difficult because it is personal, and most often, people do not like to share their personal experiences with others when there is a chance for them to be critiqued. However, these experiences also make some of the best essays because they allow the writer to develop voice and describe the event in detail. To find a good topic for this prompt, you can use a personal experience or an experience about someone you know. Usually this will be written in first person and past tense. Begin by explaining the event and the decision you had to make. When writing you want to use details to make the reader understand why you chose this event over another. It can be as simple as choosing to obey your parents when they told you not to go to a party and how your decision – whether you chose to go to the party or not – affected you at the time and how it has affected you in the future. You can write about choosing friends, taking drugs, helping someone in need. There are endless possibilities. I hope this helps give you an idea how to start. Good luck with your essay.
By choosing the one you think is the right decision that would have not affect or ruined your life. A decision that you could benefit for yourself for your own good. But it doesn't mean that you just need to think for yourself but, try to make a thing that you think you could help other people who are in need.
The most important decision is to either stay at your job or start your own business. I have done both, and the decision can be equally draining, and emotionally challenging.