Penny: If I was at a train station and one train could take me to my current job and the other train could take me to an audition for a movie, which train should I get on?
Sheldon: Are you using trains to trick me into giving you advice?
Penny: No.
Sheldon: All right then. You should take a third train where you audition for the movie, but hold off on making a career decision until you have more information.

Leonard: Some times Raj and I feel pushed aside.
Raj: Yeah. Like when you took Sheldon to Texas and showed him all around NASA. You didn't even think to ask me and Leonard.
Howard: You know what, you're right. I should have asked you.
Sheldon: And if he does ask you, go. It's amazing.

Howard: Now if we're talking about being left out, you guys went to Skywalker Ranch without us.
Sheldon: Oh, I recommend that too. That was a magical experience.

Leonard: Wait a minute. Sheldon spent a whole day with James Earl Jones and never told any of us.
Sheldon: I sure did. My goodness. From Jabba's head to ice cream with Darth Vader, I'm having a heck of a ride.

Alien: That soft pink alien looks delicious. I could eat.
*Sheldon performs Vulcan salute*

Bernadette: Well, now you get to go back as a successful scientist.
Amy: With a beautiful girl on your arm.
Sheldon: And a pointy hat sticking out of your eyeball.

Howard: Just flip the switch until the lights on the drone change to solid yellow.
Sheldon: All right, that seems simple enough. Initiating calibration sequence. *flips switch rapidly* One, two, three, four, five, six, seven, eight, nine, ten. *lights on drone turn solid yellow* Well, I suppose ten is technically "at least ten." But they're still getting at least one angry letter.

Howard: Now I rotate it horizontally on its center axis until the lights turn green.
Sheldon: Initiating rotation sequence. Don't look at me. Initiate.

Sheldon: We did it! Oh! God, if it's this much fun to rotate, imagine when we fly it.

Sheldon: You can't return it. Howard wiped his bottom with the warranty.
Raj: What?
Sheldon: I think metaphorically. But he was in the bathroom for a while.

Sheldon: Sorry. Ah, maybe it's for the best. I hear locomotive smoke is the second leading cause of death among train aficionados.
Raj: What's the first one?
Howard: Suicide.
Sheldon: Wrong. Obesity.

Raj: You guys don't have to go to the trouble. I'm back in the money now. I can just buy another helicopter.
Howard: It's not about the money. It's about solving a problem. It's why I became an engineer. It's what I like to do, it's what I'm trained to do. It's who I am.
Sheldon: Oh, look at you, the little engineer that could.

Leonard: So you really think they liked it?
Penny: Oh, sweetie, it was the best speech I--
*Drone comes through the door, knocking Penny and Leonard off their feet*
Sheldon: Don't worry, everyone in here is safe.

Amy: Do you think the moms will get along?
Leonard: I don't know. They're pretty different.
Sheldon: Maybe they'll be best friends. One of them is brilliant, one is sweet and simple.
*to Leonard*
Sound familiar?

Beverly Hofstadter: But look how well you turned out.
Sheldon: I'd feign modesty at this point, but who would believe me?