Tool is one of those bands that, despite having a truly massive fan base for decades, never quite gets the accolades it perhaps deserves from the mainstream at large. It's just a little too "weird", as anyone who's seen their music videos or live performances can attest.

Apart from their four Grammy awards?

Somewhat counter-intuitively, a band having won Grammies doesn't mean much when it comes to whether their albums show on this list. The top several award-winning groups aren't represented on the list at all: https://en.wikipedia.org/wiki/Grammy_Award_records#Most_Gram...

Preach brother! How about the list not containing Iron Maiden. Not even Number of the Beast