Jack (after failing to save Colleen): Time of death... (realizes that there is no clock) She's gone.

Jack: Maybe I was wrong!
Kate: No, you were right!

Jack: Why are you running, you DON'T EVEN KNOW WHAT YOU'RE RUNNING FROM!

Jack  : What happened?
Kate  : We're at the hatch.
Jack  : Wait, they built it.
Kate  : Yeah...They built it.
[Sawyer wakes up and kicks down into the crater of the destroyed hatch]
Sawyer: You were wrong!
Kate  : Sawyer!
[Sawyer climbs down into the crater to continue to fight Jack]
Sawyer: That's the damn hatch, just like when we left it when we started jumping through time!

Jack [to Locke]: Well, John, let me ask you this: we don't have a long term plan for the button, but we keep pushing it, don't we? Look, until we know who he is - whether or not he's telling the truth - we have to keep doing what we're doing. If you've got a better idea, let's hear it.
Gale [faintly, from his cell]: Why don't you let me go?

Jack: - Hello?
Jane (The Secretary): Dr. Shephard? Just confirming your 11:00 consult with Ms. Berenberg. It was moved up yesterday, and I know how you are with your calendar.
Jack: Yeah. Yeah, I remember, Jane. I'll, um... I'll be in there.
Jane (The Secretary): Thank you, doctor.
Jack: All right. Bye.

Jack: [about airplane turbulence] It's normal.
Rose: Oh, I know, I just never been a really good flyer. My husband keeps reminding me that planes wanna be in the air.
Jack: He sounds like a very smart man.

Jack: [After explaining what the surgery for Ben's cancer will entail] You need to be in surgery yesterday.
Ben: Alright then, whatever you need, it's yours. I'm ready.
Jack: No, I think you misunderstood me. I didn't say I was gonna do it. I just wanted you to understand how you're gonna die.[Ben and Juliet are astonished] You think I believe you people? You think I trust you? You think I'm just going to do the surgery and then I'm just gonna hope that you let me go?!
Juliet: Jack!
Jack: NO, DON'T!
Ben: Well Jack, I'm very disappointed in your decision.
Jack: Well Ben, at least you won't have to be disappointed for very long.

Jack: [after Kate persuades a semiconscious Sawyer to swallow medicine] That was good. I, uh, never learned the whole whisper-in-his-ear thing in medical school.

Jack: [as Boone is trying to give CPR to Rose] Stop! Her head's not tilted back enough, you're blowing air into her stomach.
Boone: Are you sure? That was exactly what I was doing. I'm a lifeguard, I'm licensed.
Jack: Yeah, well you seriously need to think about giving that license back.
Boone: Maybe we should do one of those hole things? You know, stick the pen in the throat?
Jack: [sarcastically] Yeah, good idea, you go get me a pen!
Boone: Hey, does anyone have a pen?

Jack: [diagnosing Sawyer] Have you ever had sex with a prostitute?
Sawyer: What's that got to do with my headaches?
Jack: Maybe a lot.
Sawyer: ...yes.
Jack: Have you ever contracted an STD? [Sawyer is silent] I'll take that as a yes. When was your last outbreak?
Sawyer: Go to hell, Doc.
Kate: I know he deserved it, but...
Jack: He needs glasses.

Jack: [on Charlie's scant collection of responses to the "blood type" question] You only asked four people?!
Charlie: I asked the whole sodding camp! Nobody knows their blood type! Most don't know their blood type! I don't know my own bloody blood type!

Jack: [on helping Sawyer] ...all I'm gonna get is a snappy one-liner, and, if I'm lucky, a brand-new nickname.

Jack: [Reading to Aaron] "Alice took up the fan, and as the hall was very hot she kept fanning herself all the time she went on talking, dear, dear. How queer everything is today. And yesterday,things went on just as usual. I wonder if I've been changed in the night. Let me think. Was I the same when I got up this morning? But if I'm not the same, the next question is, 'who in the world am I?' Aha, that's the great puzzle."

Jack: [screaming at the top of his lungs] TELL ME WHERE MY FRIENDS ARE!!!!!!!!!!!!!!