What is the single best vitamin to take?

I'm curious, when it comes to vitamins, is there one that stands out as the most beneficial to take on a regular basis? Is there a specific vitamin that experts recommend for overall health and wellness? And if so, what makes this particular vitamin so effective? Is it a multivitamin, or a single vitamin that targets a specific need? I'm eager to learn more about the best option for optimizing my health through vitamin supplementation.