Best episodes -
Season 1:
The Color of Truth - Sam leaps into Jesse Tyler, an aging black chauffeur in the segregated South. He must save his wealthy white employer (the widow of the former Governor of Alabama) from dying in a car crash, while persuading her to play a more active role in the civil rights movement. This is the first episode where Sam has no love interest — his host is a widower. Al has his first experience being noticed by a human other than Sam, although she only perceives him as a ghostly voice. (This episode is partly an homage to the play Driving Miss Daisy.)
Season 2:
Jimmy - Sam leaps into Jimmy LaMotta, a mentally handicapped young man that needs to show he can keep his job at the docks or else he will die in a mental institution. Michael Madsen guest stars as a dock worker that teases and intimidates Jimmy for being disabled. It's also revealed that Al had a younger sister who was mentally distinguished mentally-challenged and died in an institution.
M.I.A. - Sam leaps into police detective Jake Rawlings, and is caught between two missions; saving his partner's life and preventing a young woman from losing hope for her husband who is MIA in Vietnam... a situation made even more awkward by the fact that the woman in question is Al's first wife.
Season 3:
The Leap Home - Sam leaps into himself as a high school teenager and attempts to change the lives of his father, younger sister and older brother.
The Leap Home Part II - Vietnam - Sam leaps into Herbert "Magic" Williams, a soldier in his brother's platoon in Vietnam, where he is given the chance to keep his brother from dying, but at a terrible price.
Season 4:
The Leap Back - Sam and Al switch roles after a lightning strike. This allows Sam to return home to his wife, but when Al leaps into Captain Tom Jarrett, he is set to be killed by his lover's jealous ex-fiance, Sam must act as his hologram in order to save Al and continue to leap through time.
The Wrong Stuff - In a very bizarre one-off out-of-human host, Sam leaps into one of a group of chimps named Bobo that are bound to be destroyed in an Air Force testing experiment.
Roberto! - Sam is Roberto Gutierrez, a Geraldo Rivera-inspired talk-show host who works with his co-worker to unmask a local fertilizer and pesticide plant that is researching and producing chemical weapons... before they're silenced.
A Leap for Lisa - Sam leaps into a younger Al who is on trial for the murder and rape of his commander's wife, but when Sam's actions unintentionally prevent the witness whose testimony cleared Al in the real history from testifying before she dies, things take a turn for the worse as Sam suddenly finds himself with a renamed Ziggy (Now called 'Alpha'), a married Gushie and Tina, and a new Observer (guest star Roddy McDowall) Terry Farrell and Charles Rocket guest star.
Season 5:
Lee Harvey Oswald - BEST EPISODE OF QUANTUM LEAP EVER Sam leaps into various points in Lee Harvey Oswald's life in an effort to seemingly prevent him from killing President John F. Kennedy, but the objective is made more complex by the fact that their minds are merging; if Al can't bring Sam back, it will be Sam Beckett who pulls the trigger on Kennedy that fateful day in Dallas. In the end, Sam leaps into Secret Service agent Clint Hill who climbed on the back limousine during the assasination. In the episode dénouement Al reveals that an alternate history had previously occured where Jackie Kennedy also died and Sam's actual mission was to save her.
Deliver Us From Evil - Sam leaps back into Jimmy LaMotta, but is perplexed when he finds that the happy future he supposedly ensured in his previous leap is not taking place, and his brother's marriage is falling apart. Shortly thereafter, Sam finds something he never expected; a female quantum leaper named Alia, apparently there to "put wrong what once went right".
Goodbye Norma Jean - Sam is Dennis Boardman, the chauffeur of Marilyn Monroe and must help the unhappy star stay alive to make one final movie.
The Leap Between The States - Breaking all the rules of Quantum Leaping, Sam leaps along his genetic line and finds himself in the American Civil War as his great-grandfather, Captain John Beckett, of the Union Army. While helping the underground railroad smuggle a family that one of which is the grandfather of Dr. Martin Luther King, Jr. to freedom, Sam must also win the heart of his great-grandmother, or he may be erased from existence.
Memphis Melody - As Elvis Presley, Sam must help a struggling female musician, but at the same time must ensure that he doesn't prevent the king of rock n' roll from being discovered. Last brush with History: Sam is preceded onstage at a talent show by a blond seven-year-old with sunglasses and a saxophone, introduced as "Little Billy C. from Hope, Arkansas". Could it be future President Bill Clinton?
