Eddie Murphy, in the moment

Eddie Murphy's rollercoaster movie career has taken him from the giddy heights of Trading Places to the rock bottom of Norbit. Yet every time I write him off as one of those self-exploiting Saturday Night Live stars (see: Chevy Chase, Will Ferrell, Mike Myers) who has come to the point in his career where he just takes the money and runs, Murphy turns in a indelible performance like that of Jimmy "Thunder" Early in Dreamgirls, a Marvin Gaye-like soul-singer, or a quietly funny turn like that of Evan Danielson in Imagine That (opening tomorrow), a workaholic dad who discovers fatherhood is as fulfilling as finance.

Someone (Machiavelli? Castiglione?) once observed that revenge is a dish best served cold. Eddie Murphy is an actor best served raw. When he's in the moment, as he is in  48 Hours,  Trading Places, Beverly Hills Cop, Dreamgirls and the feel-nice Imagine That opposite the adorable seven-year-old Yara Shahidi, you can see his improvisatory joy. There wasn't time for him to overthink -- and overcook -- his performance. My favorite Eddie Murphy performances? Trading Places, Bowfinger and Dreamgirls.  And, of course, as Donkey in Shrek. Yours?