I can’t answer this without mentioning my favorite bands. So I’ll focus on cultural impact, and you can’t talk about that without mentioning The Beatles.
They changed the way albums were conceived, pushed the boundaries of what could be done in the recording studio, and proved that pop music could be as ambitious and artistically significant as literature or film.
I could go on for hours about how Radiohead completely redefined what alternative rock could be, blending electronic music, jazz, classical influences, and experimental production into something entirely their own. Their willingness to reinvent themselves with every album is one of the reasons they’re still one of the most influential bands of the modern era.