Eddie Murphy in '48 Hrs.'

His distinctive laughter is the only constant in his career. The contagious guffaw, the low-throated "he he he" of Eddie Murphy has served him well ever since he first came to attention on Saturday Night Live in the early 1980s. Murphy's laugh will be heard again as the voice of the good-natured sidekick Donkey in Shrek Forever After, which opens in general release on May 21. The Shrek films, unfortunately, reflect the trajectory of Murphy's movie career as a whole: a great start, followed by a gradual decline into repetition, indifference, and a general dulling of a sharp comedic sensibility.

Dreamgirls gave him a shot at shaking off the wreckage of a long, disastrous stretch in which he played down to a juvenile audience. Following up his Academy Award-nominated turn in an dramatic musical with Norbit may have been financially rewarding, but immediately dumped him back into the lowest-common-denominator slop bucket of The Nutty Professor, Doctor Dolittle, and Daddy Day Care. (Not that dull action fare like Showtime, The Adventures of Pluto Nash, or I Spy did anything to advance his cause.)

The decade of disappointment makes his earlier triumphs stand out in sharper relief. Trading Places showcased a confident young comic actor; Beverly Hills Cop proved he could blow people away with both wisecracks and firearms; Coming to America demonstrated his versatility; Bowfinger showed he could still steal the show in a supporting role. His ambition and one-time desire to expand his range make Harlem Nights, Boomerang, and The Distinguished Gentleman stand out. His best role, however, was his very first.

Eddie Murphy in '48 Hrs.'As Reggie Hammond in Walter Hill's 48 Hrs., Murphy gets to be funny, physical, dramatic, sexy, and confident. We're introduced to him as he's singing "Roxanne" in a high falsetto in his prison cell. Reggie was convicted of armed robbery, but his old gang has been shooting up San Francisco, killing a cop in the process, and Detective Jack Cates (Nick Nolte) wants to put a stop to it. So he springs Reggie from prison on a temporary furlough to help him catch the bad guys.

The film established the "buddy cop" template for the 1980s. Jack is an old school cop, happy to beat up criminals and witnesses to further his investigation. He drinks heavily and has a beautiful girlfriend (Annette O'Toole) he doesn't appreciate. Reggie may not be a cop, but he has his own unique, new school methods, as when he enters a redneck bar and demands answers in a classic sequence.

Reggie has terrific nerve, or so we think. Not only does he take complete control of a bar full of rednecks, he stands up to the taller, broader Jack with aplomb. Later, though, we see that he's not as tough as he pretends. Confronted with a life or death situation, he flinches; his bravado fails him completely. We feel for him -- by that point, he's the deserving underdog / lovable criminal we're meant to adore -- and it's only a matter of time before he must reassert his manhood if he's ever to walk proud in town again.

48 Hrs. is aggressively retro in its attitudes. Women are nothing more than sexual playthings; men must prove they are men through violence; murder solves everything. It's a very Old West show, yet Murphy, a young African-American comedian making his film debut, walks away with the movie. It is, to be sure, a very good movie, a rollicking, lightning-paced action comedy / drama, directed by the great Walter Hill at the top of his game. Nolte is a very solid, charismatic, if grizzled leading man.

Still, it's Eddie Murphy who makes the most lasting impression in his best role to date.