No question Led Zeppelin is/was the best band of all time.
Led Zeppelin are widely considered to be one of the most successful, innovative and influential bands in the history of music. Rock critic Mikal Gilmore said, "Led Zeppelin—talented, complex, grasping, beautiful and dangerous—made one of the most enduring bodies of composition and performance in twentieth-century music, despite everything they had to overpower, including themselves".
Led Zeppelin have influenced hard rock and heavy metal bands such as Black Sabbath, Rush, Queen, Megadeth, Velvet Revolver, Tool and Dream Theater. They also influenced some early punk and post-punk bands, among them the Ramones and The Cult. They were also an important influence on the development of alternative rock, as bands adapted elements from the "Zeppelin sound" of the mid-1970s, including The Smashing Pumpkins, Nirvana, Pearl Jam and Soundgarden.
Led Zeppelin have been credited with a major impact on the nature of the music business, particularly in the development of album-oriented rock (AOR) and stadium rock. In 1988 John Kalodner, then-A&R executive of Geffen Records, remarked that "In my opinion, next to the Beatles they're the most influential band in history. They influence the way music is on records, AOR radio, concerts. They set the standards for the AOR-radio format with 'Stairway to Heaven,' having AOR hits without necessarily having Top 40 hits. They're the ones who did the first real big arena concert shows, consistently selling out and playing stadiums without support.
Led Zeppelin had a major influence on the record business, and the way rock concerts were managed and presented to huge audiences. The band have sold over 200 million albums worldwide according to some sources, while other sources state that they have sold in excess of 300 million records, including 111.5 million certified units in the United States. According to the Recording Industry Association of America, Led Zeppelin are the fourth highest selling music act in the US and one of only three acts to earn four or more Diamond albums. Led Zeppelin remain one of the most bootlegged artists in the history of rock music.