Final answer:
The best Call of Duty game varies by personal preference; however, the Modern Warfare and Black Ops series are often favorably cited due to their impact, narrative, and gameplay variety.
Step-by-step explanation:
Determining the best Call of Duty game is largely subjective and depends on personal preference, playstyle, and what aspects of the game one values most. Some players may prefer the classic feel and in-depth narrative of the Modern Warfare series, while others might enjoy the futuristic elements of Infinite Warfare or Advanced Warfare. Still, others might appreciate the historical settings of games like World War II or the versatility and zombie modes of the Black Ops series.
Comparatively, sales figures and critical reception can serve as indirect measures of a game's success and popularity. The Modern Warfare series, particularly Modern Warfare 1 (also known as Call of Duty 4: Modern Warfare), has often been cited for its revolutionary impact on the first-person shooter genre. Meanwhile, the Black Ops series has maintained a strong following due to its gameplay variety and engaging story. Both series have had multiple installments that were positively reviewed and well-received by the gaming community.