Final answer:
Adele's most popular song so far is "Someone Like You," from her album "21." The song achieved international success, topping charts, winning awards, and becoming a signature piece representative of her emotional style and powerful vocals.
Step-by-step explanation:
Adele's most popular song so far is widely considered to be "Someone Like You." This heartfelt ballad from her second studio album, titled "21," garnered widespread acclaim. Highlighting Adele's powerful vocals and emotional delivery, the song resonates with themes of heartbreak and acceptance after a breakup. Upon its release, "Someone Like You" topped the charts in multiple countries and earned a number of awards, including a Grammy for Best Pop Solo Performance. Its accompanying music video also helped to cement the song's popularity, featuring a somber Adele walking through the streets reflecting on lost love.
The impact of "Someone Like You" extends beyond the charts. It's often celebrated as one of Adele's signature songs and has been used in various films, television shows, and commercials, further demonstrating its lasting relevance in popular culture. Adele's powerful storytelling through music continues to resonate with audiences around the world, and "Someone Like You" stands as a testament to her musical legacy.