Lars Ulrich's favourite Metallica album will always be "the next one".
The 'Enter Sandman' drummer prefers to focus on the future of the heavy metal legends rather than dwelling on what they've done in the past, and he thinks "that attitude" plays a role in the group's longevity 36 years after debut album 'Kill 'Em All'.
He told Pollstar: "I keep thinking and forcing myself to think all our best years are still ahead of us.
"It's always, 'What's your favorite record?' It's the next one, the one we haven't recorded yet.
"It's always about the possibilities, always about what can be, what's coming. That, to me, is what this is all about and I think that attitude is a big part of the why Metallica still connects to so many people around the world."
His comments come after Pollstar's study suggests the 'Nothing Else Matters' rockers are the "biggest all-time touring band", grossing $1.4 billion in ticket sales since 1982.
The research uses stats from the beginning of the band, with 22.1 million tickets sold over the years.
They've also played in 48 countries across all seven continents - including Antarctica - which few touring bands can claim.
Meanwhile, Lars previously credited The Rolling Stones with resurrecting Metallica and helping bring them back from the brink after a fallout in 2004.
They invited the band to support them on two dates of their 'A Bigger Bang' tour in San Francisco in 2005, which were Metallica's only shows that year.
Lars said: "That was the last time we had a real break - we haven't shut down the band in 14 years, but we disappeared then for about a year.
"And then The Rolling Stones called us up and said, 'Come and play some shows with us in California,' and we sort of agreed you're not going to say no to the Stones, so that was it.
"It gave us the way to start it back up again. Whether you're a team in an office or a bunch of dudes in a rock and roll band, at some point people have to figure out how to get along and work as a team."