10. "The Man From Tallahassee," Season 3, Episode 13We find how John Locke came to be in his wheelchair, having fallen eight stories after being pushed out of a window by his biological father, Anthony Cooper. On the island, Ben tells Locke about a magic box and how something very peculiar came through it, a man from Tallahassee named Anthony Cooper.
Best moment: Ben and Alpert lead Locke down a corridor to a locked door. They unlock it, revealing a bound and gagged Cooper. Locke, obviously confused, responds with a hesitant "Dad?"
9. "The Incident," Season 5, Episode 16-17
After being sent back in time, Jack and the rest of the Oceanic 6 (minus Sun) try to reset the timeline that brought them to the island by exploding an atomic bomb where the Swan hatch is to be built.
Best moment: As the episode opens, we finally meet the iconic Jacob sitting on the beach in what appears to be the 1800s. He is met by the Man In Black, who declares that one day he will find a loophole to kill him. Jacob, unfazed, replies "When you do, I'll be right here." As the episode ends, we learn that Locke's body has been taken over by the MIB, who has convinced Ben to murder Jacob.
8. "The Life and Death of Jeremy Bentham," Season 5, Episode 7
Locke leaves the island to bring back the Oceanic 6 while dealing with the fact that both Christian Shepard and Richard Alpert have told him he will have to die in order to accomplish his mission.
Best moment: Ben finds Locke at just the right moment in his hotel room, preventing his suicide. Ben convinces Locke that he is too important to die and Locke explains his whole mission. After squeezing every last bit of info out of him, Ben proceeds to murder Locke with the very rope Locke would have killed himself with.
7. "Pilot," Season 1, Episode 1
Arguably the most cinematic pilot ever filmed. Originally broadcast on Sept. 22, 2004, the pilot opens with the aftermath of a plane crash.
Best moment: After venturing into the jungle looking for the plane's cockpit, Jack, Charlie and Kate make their way back to the beach with a radio they found. They manage to tap into a French transmission that is being broadcast from the island. The translated transmission states "It killed them. It killed them all." This prompts Charlie to utter the classic line, "Guys, where are we?"
6. "Walkabout," Season 1, Episode 4
In the pilot, John Locke is running around the beach helping others after the crash. In "Walkabout," Locke isn't running around anywhere. He's bound to a wheelchair.
Best moment: The stranded Losties decide to hold a makeshift memorial for the deceased passengers of Oceanic Flight 815. They burn the fuselage and hold a small ceremony. Locke stands on the outskirts of the group, staring at his wheelchair silhouetted against the flames.
5. "Greatest Hits," Season 3, Episode 21
Desmond has confessed to Charlie that he has seen the future and unfortunately Charlie will have to die to save others. Charlie accepts his fate and compiles a list of the five greatest moments of his life.
Best moment: Charlie recalls his greatest moment, the night he met the girl he loves, fellow castaway Claire.
4. "Through the Looking Glass," Season 3, Episode 22
The Season 3 finale is a game changer. On the beach, the battle between the Others and the survivors comes to a head while Charlie drowns before warning Desmond that an approaching boat may not have the best intentions.
Best moment: Viewers have gotten used to the interlaced flashbacks regarding our Losties. In this episode, the story revolves around Jack's alcoholism and depression. But it's revealed that this is not a flashback, but a glimpse into the future.
3. "Ab Aeterno," Season 6, Episode 9
The back story of Richard Albert comes front and center. In 1867, Alpert is imprisoned for accidentally killing a doctor, then sold as a slave and subsequently shipwrecked on the island.
Best moment: The four-toed statue has been a mystery since season one. In season five, it's glimpsed in full form. In this episode, it's destroyed, the victim of a tsunami that also brought in the Black Rock.
2. "The Shape of Things to Come," Season 4, Episode 9
In one of the series' more powerful episodes, it is revealed that the freighter folks are actually on the island to kill Ben Linus. Led by Martin Keamy, the freighter dudes lead an assault on the Losties at the barracks, with deadly results. Ben summons the smoke monster, which shows up and manhandles the freighter crew.
Best moment: Keamy and the others surround Ben's cabin with his daughter, Alex, in custody. They threaten to kill her if Ben doesn't surrender. Ben tells Keamy that Alex is "not my daughter. I stole her as a baby from an insane woman. She's a pawn. Nothing more." To his amazement, Alex is killed.
1. "The Constant," Season 4, Episode 5
Sayid and Desmond encounter turbulence in a helicopter as they make their way to the freighter. This causes Desmond to experience some very strange side effects: his consciousness begins to travel through time. In order to "cure" himself, Desmond must find his "constant," something that is present in both timelines that he sincerely cares about. His constant is his true love, Penny.
Best moment: In the past, Desmond tells Penny that in eight years he will call her. Back in the present, he calls her, leading to one of the most heartfelt moments of the series. She tells Des that she has been searching for him. They exchange "I love yous" before the phone battery dies.
