What are the 3 best vitamins?

Could you please elaborate on what you consider to be the three best vitamins, and why they are particularly important for maintaining good health? Are there any specific health benefits associated with each of these vitamins, and are there any dietary sources that are particularly rich in them? Additionally, are there any potential risks or side effects associated with taking these vitamins in supplement form, and should individuals consult with a healthcare professional before incorporating them into their diet?