What is the most famous ETF?

Could you please elaborate on what the most renowned ETF is? I'm interested in understanding its popularity, its investment strategy, and how it has managed to achieve such widespread recognition. Also, I'm curious to know if it's suitable for a diversified investment portfolio and what kind of returns investors have generally enjoyed. Could you provide some insights into its historical performance and any potential risks associated with investing in it? Additionally, are there any specific criteria or factors that make it stand out from other ETFs in the market? Thank you for your help in answering these questions.