Kill 'Em All (originally titled Metal Up Your Ass) brokers an alliance between deadly adversaries: punks and metalheads. It contains the first great Metallica standard, "Seek and Destroy." 

 Ride the Lightning was a titanic step forward for Metallica, codifying a format for the following two records: blitzkrieg opener, epic title track, spooky death march, slow-building ballad, three or four more thrashers, and an instrumental. 

 Master of Puppets is the apogee of thrash metal, and as thrilling an album as you’ll ever hear on the subjects of cocaine addiction (the title cut), the glory of metal itself (“Battery”), and that crucial 1980s-metal target televangelism (“Leper  

 Bassist Cliff Burton died in a bus crash in 1986, and the band became more solemn. Justice for All took thrash to its logical conclusion: The tracks grew ever more labyrinthine, and the band became preoccupied with war, censorship, and other "important issues. 

 After eight years of railing against the mainstream, the mainstream came to Metallica. The nightmarish "Enter Sandman" is second only to "Smells Like Teen Spirit" as the most startling rock single of 1991. The rest of the record features more lucid songwriting and better recording values than any... 

 Metallica reemerged after five years off with Load, which included, for the first time, songs written in a major key. The genre experiments and Hetfield’s maturing singing may have distressed metalheads, but the filler quotient is low, and Load is their most underrated record.  

 Reload consists of Load's leavings, and sounds like it. 

 Throughout its career, Metallica released cover tunes on B-sides and EPs. Garage, Inc. pairs one disc consisting of every one of those, including 1987's rip-snorting Garage Days Re-Revisited, with another of newly recorded tributes. 

 Garage was followed by their very worst disc: S&M (Symphony and Metallica) is just as useless as every other album on which a rock band plays their hits with an orchestra.  

 St. Anger was a mea culpa to longtime devotees as the now Newsted-less trio crafted a complex riff marathon once more, this time accompanied by cathartic lyrics from a newly sober Hetfield. But production odditiesare jarring and poor guitarist Kirk Hammett is rewarded with no solos. 

 2008's Death Magnetic was the skull-rattling old-school album that St. Anger wasn't, an epic speed-metal romp that recalled Metallica's Eighties work. With Rick Rubin producing, everything sounded appropriately full-bodied.