What is the most popular Clash song?

The most popular Clash song is widely considered to be "Should I Stay or Should I Go", released in 1982 as a single from their album "Combat Rock". The song became an instant hit and reached number one on the UK Singles Chart, remaining there for two weeks. It also achieved significant popularity in other countries, reaching the top 10 in several other charts worldwide. "Should I Stay or Should I Go" is known for its catchy lyrics, powerful guitar riffs, and energetic rhythm, making it one of the most iconic and beloved Clash songs among their fans.