The band's most successful release, The Dark Side of the Moon spent 741 consecutive weeks (14 years) on the USA-based Billboard 200 album chart, the longest duration of any album in history. Additionally, the album holds the record of spending the highest amount of time on the Billboard charts, staying there for more than 1,500 weeks (almost 29 years). It is one of three albums tied for the claim of second highest selling album globally of all time, selling forty million or more units. In addition to its commercial success, The Dark Side of the Moon is often considered to be the group's defining work, and is still frequently ranked by music critics as one of the greatest and most influential albums of all time. -Wikipedia