Alex: Well, I know she loves playing the harp, so I found this beautiful music box that plays one of her favorite songs.
Sheldon: Now, Amy already has a real harp and it can play any song. What are you trying to pull here?

All: By the power vested in us, by the state of California...
Sheldon: And the Klingon High Council...

Neil Gaiman: You know, if you're interested in alternate histories, Neil Gaiman wrote one called 1602.
Sheldon: I'm sorry, we're in the middle of something here.
Neil Gaiman: It is pretty good, actually. He takes the Marvel superheroes and he puts them into Elizabethan England.
Sheldon: Let me guess, everyone thinks the X-Men are witches.
Neil Gaiman: Yeah.

Sheldon: You know, I also have a date tonight. But don't worry, it's not another woman. It's string theory.

Sheldon: Well, Howard, thank you. It's quite a gesture on your part. You've shown yourself to be the bigger man.
Howard: Thank you.
Sheldon: Which I found totally unacceptable. I must be the bigger man. Therefore, you may use my spot until such time as I learn to drive or get a Batmobile.

Penny: When I was a senior in high school, one of my friends heard I was gonna be named head cheerleader, I was so excited. My mom even made me a celebration pie. Then they named stupid Valerie Mossbacher head cheerleader, big old slutbag.
Sheldon: Are you saying that you think a celebration pie is even remotely comparable to a Nobel Prize?
Penny: Well, they're pretty tasty.
Sheldon: And on a different, but not unrelated topic, based on your current efforts to buoy my spirits, do you ever truly believe that you were fit to be a cheer leader?

Leonard: Sheldon, relax. She doesn't have any symptoms, I'm sure she's not contagious.
Sheldon: Oh, please. If influenza was only contagious after symptoms appear it would have died out thousands of years ago. Somewhere between tool-using and cave-painting, Homo habilis would have figured out to kill the guy with the runny nose.

Sheldon: That's my parking spot.
Raj: Why do you have a parking spot? You don't have a car. You don't even drive.
Leonard: Maybe they reassigned it because you never use it.
Sheldon: Well, I'm not using my nipples either. Maybe they should reassign those.

Leonard: It's 3 in the morning!
Sheldon: 3 in the morning is a good time for bongos.
Leonard: I was sleeping!
Sheldon: Leonard sleep while I play bongos.
Leonard: No, I don't.
Sheldon: Leonard no sleep while I play bongos.

Sheldon: Priya, if you're experiencing any tension or awkwardness, it may stem from the fact that Leonard and Penny used to, if I might quote Howard, "Do the dance with no pants".

Sheldon: The horror!
Penny: Sheldon, I'm sure it's going to be fine.
Sheldon: No, it's not going to be fine. Change is never fine. They say it is, but it's not.

Amy: Sheldon.
Sheldon: What? Did you finish? Great job.

Sheldon: Thank you, Dr. Fowler. I have a very long and somewhat self-centered speech here. But I'd like to set it aside.
Penny: Yeah!
Howard: Way to go!
Sheldon: Because this honor doesn't just belong to me. I wouldn't be up here if it weren't for some very important people in my life. Beginning with my mother, father, meemaw, brother and sister. And my other family, who I'm so happy to have here with us. Is that Buffy the Vampire Slayer? I was under a misapprehension that my accomplishments were mine alone. Nothing could be further from the truth. I have been encouraged, sustained, inspired and tolerated not only by my wife, but by the greatest group of friends anyone ever had. I'd like to ask them to stand. Dr. Rajesh Koothrappali. Dr. Bernadette Rostenkowski-Wolowitz. Astronaut Howard Wolowitz. And my two dearest friends in the world, Penny Hofstadter and Dr. Leonard Hofstadter. I was there the moment Leonard and Penny met. He said to me that their babies would be smart and beautiful. And now that they're expecting, I have no doubt that that will be the case.
Penny: Thanks, Sheldon. I-I haven't told my parents yet, but thanks.
Sheldon: Oh. I'm sorry. Don't tell anyone that last thing. That's a secret.
Howard, Bernadette, Raj, Penny, Leonard, I apologize if I haven't been the friend you deserve. But I want you to know in my way, I love you all. And I love you. Thank you.

Leonard: What?
Amy: Sheldon has something he'd like to say.
Sheldon: I'm sorry I didn't react appropriately. You and Penny are bringing new life into the world. Congratulations. I can't wait to meet it.
Leonard: "It"?
Sheldon: That's a gender-neutral pronoun. If you're offended, take it up with the English language.

Leonard: Are you kidding me? You just found out that a woman who has loved and cared for you for 12 years is pregnant, and all you can say is you're relieved that she's not gonna get you sick?
Sheldon: There's no need for a recap. I was there.