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20 Greatest Sci-Fi TV Shows

8. QUANTUM LEAP
(1989-1993)
A stirring drama touching on issues such as race, feminism, and homophobia, Leap cloaked its social commentary in the guise of time-travelly goodness. The premise was uncomplicated: An experiment gone awry sends scientist Dr. Sam Beckett (Scott Bakula) bouncing through time, inhabiting the lives, and bodies, of folks from the last 60 years. Only by saving the downtrodden, with the aid of holographic pal Al (Dean Stockwell), can the good doc leap into the next adventure and, maybe, leap home. Bakula was a wonder portraying everyone from an elderly African-American man to a pregnant teenage girl to Elvis Presley, but much credit goes to creator Don Bellisario, who reminded us with each nuanced episode that the human condition — and the comic appeal of cross-dressing — is timeless. —Paul Katz