Who is the king of antibiotics?

Could you elaborate on the notion of a "king of antibiotics"? Is this a metaphorical term referring to the most effective or widely used antibiotic, or is there a specific antibiotic that holds a prominent position in the medical community due to its unique qualities or historical significance? If the latter, which antibiotic would you consider to be the "king" and why do you think it holds that title? Are there any controversies surrounding this particular antibiotic, or is it widely accepted as the gold standard in its field?