Starring: Dean Stockwell, Scott Bakula, Deborah Pratt
The Leap Back - June 15, 1945 - S4-E1
Corrected entry: It is accepted canon that Al sees Sam as the person he has leapt into, and Sam of course sees Al as Al. Therefore, at the beginning of this episode, Al would have been shocked to see Sam standing next to him, while Sam would not have recognized Al, but rather would be looking at Tom the soldier that Al has leapt into. However, they are unaware of the role reversal until Al walks into the cannon on the lawn.
All Americans - November 6, 1962 - S2-E14
Audio problem: During the speech where Al tells Sam to quit (to force Chewie to play), Sam says he can't quit but his mouth doesn't move for a couple seconds after the words start playing.
Al: Well, we been having some difficulty. Ziggy, he's, uh, going through mood swings. I think we need get a girl computer put it right next to him, one with a nice set of hard disks.
Sam: You would.
Permanent Wave - June 2, 1983 - S4-E5
Trivia: The little boy in this episode is Joseph Gordon-Levitt.
Mirror Image - August 8, 1953 - S5-E22
Question: I believe in the final episode, Al the bartender asked Sam where he would like to go and Sam said home. He then said he couldn't because he had a wrong to put right for his hologram friend Al, which he did. After telling Al's wife that Al is alive he leaps. I think it said after that that Sam never makes it home. So does he continue leaping forever or is he stuck in the last person he leaps into? I know he lost his memory but what happened after that?
Chosen answer: Per the Quantum leap page at http://www.scifi.com/quantum/episodes/season5.html. 8 August 1953: An enigmatic leap lands Sam in a Pennsylvania tavern, as his own grown self on the day of his birth. As Al and Gushie work frantically to locate him, Sam befriends a wise bartender (popular character actor McGill, who'd appeared in a different role in the very first "leap") and a group of coal miners. As a host of familiar-looking faces pass through the bar - with different identities than Sam remembers - Sam ponders his life of leaping with Al the bartender, who tells Sam he controls his own destiny. Pressed for more, Al the bartender simply shrugs and says, "Sometimes, 'that's the way it is' is the best explanation." Sam realizes he must right at least one more wrong before he can go home, and leaps back to tell Al Calvavicci's wife Beth (from "M.I.A.") to wait for Al, who will survive Vietnam and come home to her. The closing title cards state that Beth and Al have four daughters and will shortly celebrate their 39th wedding anniversary ... and that Sam Beckett never returned home.
Correction: While it was canon in early episodes (notably "What Price Gloria") that the Observer saw Sam as the Leapee, by the time of "Miss Deep South" (which originally aired well before "The Leap Back"), it is clear that a change has been made so that Al sees Sam as Sam. In that episode Al says that Sam looks "like Scarlett O'Hara on steroids." So for Sam and Al to initially not realize that something strange is going on at the beginning of "The Leap Back" is not a plot hole.