ELO is the best of the rest. They have the most top 40 hits on Billboard of any band that never had a #1 single, with 27. With 13 studio releases, they have sold over 50 million albums, not including singles. And while their commercial success is unquestioned, their continued popularity after their dissolution is a testament to the mark they left on music.
This is also perhaps the only band which spawned a literal sequel, which formed after Bev Bevan left to drum for Black Sabbath and then wished to reform the band after ELO's demise. Since the name "Electric Light Orchestra" was co-owned by singer, song writer and guitarist Jeff Lynne, Bevan formed ELO Part II. Lynne wasn't interested in reforming ELO, since he was busy working with George Harrison, Roy Orbison, Bob Dylan, and Tom Petty as "The Traveling Wilburys."
ELO's sound is hard to define, as it combines many musical genres. Often described as rock with a classical influence, they also found quite a following among fans of disco. Their music is often heard in movies and television commercials to this day.