5x03 - Broken Ties

John: You got anything?
Rodney: Ah, nothing. I tried everything. Pacing, snacking, bathing.
John: Bathing?
Rodney: Yeah, like Archimedes.
John: You mean the Greek scientist who had a crush on Teyla?
Rodney: No, like the Greek mathematician who came up with the Archimedes principle.

5x04 – The Daedalus Variations

John: What are you talking about?
Rodney: I'm telling you, she's hiding him from me.
John: She's not hiding him.
Rodney: Oh yeah? Every time I go to see him, she tells me that he's just settled down.
John: Can you blame her? You dropped him.
Rodney: I did not drop him. He jumped.
John: Jumped?
Rodney: Well, he wiggled out of my arms. Look, I said I was sorry. Besides, how much damage could I possibly have done? He fell, like, maybe two feet. Stuff like that happens all the time. I was dropped like a dozen times when I was a kid.

John: Have you made any progress?
Rodney: As a matter of fact, yes we have.
John: We?
Rodney: Me and the other McKay, who, unsurprisingly, is a genius.

Rodney: In a spectacular feat of multi-dimensional mathematics, I have discovered a way to send the ship back along the path it previously traveled bypassing the navigation system all together.
John: Wait a minute, you're talking about putting this thing in reverse?
Rodney: Exactly.
John: I just suggested that two hours ago.
Rodney: And naturally I dismissed it out of hand. But then I realized that, including the original designer, not one but two versions of myself have failed to make this work. I had to think not like me. In fact, I had to think the opposite of me, and it doesn't get more opposite than you.
John: … I'll take that as a compliment.

5x06 – The Shrine

Rodney: Been trying to remember the name of my sister's kid.
John: Betty.
Rodney: Betty? Pretty sure that's not it.
John: It's Madison. See, at least you remember what it wasn't.
Rodney: Well, it's an underrated skill.
John: I'm just saying you might not be as far gone as you think.
Rodney: I'm hiding it. Believe me, I've already forgotten more than most people will ever know. And I know that sounds… arrogant. Is that right?
John: Yeah, that works.

5x14 – Prodigal

John: Oh, you've gotta be kidding me.
Rodney: It was the next thing on my list.
John: You said you were gonna fix them.
Rodney: I know, and I was getting to it, swear.
John: And you had two years.
Rodney: I've been busy.

5x17 – Infection

John: What’s our status, Rodney?
Rodney: I’d say screwed is an apt description.

5x19 – Vegas

Rodney: I know you'll probably think this sounds ridiculous, but a...little while ago we accidentally opened a rift in space-time. Went through to an alternate version of reality, very similar to ours in many ways. Met a team much like the one I work with, only you were the leader. You were a hero... Saved the world several times over.
John: Doesn't sound much like me.
Rodney: I don't think there's much difference between you and that other John Sheppard I met. It's amazing how one incident can entirely alter the course of your life. Still... I like to believe you have the same strength of character. That's why I told you the truth.