The explosive and edgy Lethal Weapon introduced America to its favorite modern buddy team: Mel Gibson's suicidal firecracker Martin Riggs, a Vietnam vet whose reckless stunts earn him a reputation as the Los Angeles Police Department's least desirable partner, and Danny Glover's aging family man Roger Murtaugh, a veteran detective who wants nothing more than to gracefully live to see his pension. Richard Donner's smash movie is sleek, stylish, and practically nonstop action, but it's the chemistry between the combustible energy of Gibson and the paternal reserve of Glover that makes this combination so lethal. A sequel was inevitable, so Lethal Weapon 2 sent Riggs and Murtaugh after a South African drug syndicate, tossed funnyman Joe Pesci into the mix as a comic foil, and upped the ante of explosions, car chases, and apocalyptic property damage. Kung fu-kicking Rene Russo signed on for Lethal Weapon 3, a "mad genius run amok" adventure rushed into production without a finished script (and it shows in sloppy ad-libbed scenes) and crammed with wild high-speed chases and spectacular explosions. When Lethal Weapon 4 hit screens in 1998, the starring cast had ballooned: hot comic Chris Rock joined Gibson, Glover, Russo, and Pesci to take on a Chinese counterfeiting and slavery ring led by Hong Kong martial arts superstar Jet Li. Director Richard Donner helms every installment of his series, topping the frenzy of action and pyrotechnics with each new feature; watching the arc of the Lethal Weapon franchise is like a crash course in American action cinema of the '90s: bigger, faster, louder. Yet at the heart of every film is Riggs and Murtaugh, mismatched partners who become unlikely buddies, ready to lay their lives down for one another. By the climax of Lethal Weapon 4, as they team up against the fighting fury of Jet Li, their friendship has become the defining drive of the series. --Sean Axmaker