Amy: I suppose being the first people on a new planet would be incredibly exciting.
Sheldon: I know. We could be the first to plant a flag on Mars.
We could be the first to watch Mars Attacks on Mars.
We could be the first to say "Good lord, what on Mars are you talking about?"

Amy: We could also be the first people to procreate on Mars.
Sheldon: You just can't keep it in your space pants, can you?

Amy: Think about it. If we had a family there, our kids would be martians.
Sheldon: They would, wouldn't they? We could give them cool martian names. We could teach them about martian history, like who planted those flags or where'd that copy of Mars Attacks come from.

Amy: I guess we'll have to make a new video together as a couple.
Sheldon: Good idea. And as you've had such a rough day, I'm gonna let you throw the pie in Leonard's face.

Raj: Thank you for forgiving me.
Emily: It's okay. At some point we were bound to have our first fight.
Raj: Well, it almost happened when you called my Apple Pie crust doughy. But the truth is, you were right and I was just angry at myself.

Leonard: So, where do you want to hang it?
Penny: Are you kidding? We're not hanging it.
Leonard: But it's an expression of our love.
Penny: And our butts. Not hanging it.

Amy: I just read about an experiment designed to see if you can make two people fall in love in a matter of hours.
Leonard: That doesn't sound right. My research has shown it takes three to five years of shameless begging.
Penny: Honey, neither of us comes off good in that story.

Sheldon: Oh, that's nonsense. I proclaimed my love for you. And the last time I looked in your eyes was when you thought you had conjunctivitis.
Amy: Other than the fact I had it, that was a magical night.

Penny: Raj, would you ever try an experiment like that with Emily?
Raj: I don't need science to win her heart, I have my family's wealth for that.

Sheldon: We're scientists, we can conduct our own research. I propose that we imprison two street people-
Amy: No.
Sheldon: You didn't even let me finish.
Amy: Forget it.
Sheldon: Oh, so you can experiment on all the apes you want, but I want to manipulate the emotions of two captive human beings, suddenly I'm the monster.

Penny: You're okay with an experiment where you have to answer awkward questions about your innermost feelings?
Sheldon: Yes.
Penny: Please can I do it with him, please.

Sheldon: Just out of curiosity, Penny, if this experiment does make us fall in love, would you drive me to Lake Geneva, Wisconsin, for Gary-Con. It's the only convention celebrating the life and work of Gary Gygax, the co-creator of Dungeons and Dragons.
Penny: You know what, I can honestly say if we fall in love, not only will I drive you there, I will buy you all the dragon t-shirts you want.
Sheldon: Okay, babe, let's do this.

Raj: I don't believe in tempting fate. Same reason I wouldn't use a ouiji board or pick a fight with an Asian guy. Probably doesn't know karate, but why risk it?

Raj: Given the choice of anyone in the world, who would you want as a dinner guest?
Leonard: I can honestly say Penny.
Amy: Aww, then I choose a janitor, because I'm about to throw up.

Howard: Are you kidding me? You lost my mother's ashes?
Airline worker: No, I'm just saying that sometimes bags are misrouted.
Howard: All right, where did you misroute the only woman who ever loved me? The first woman - I meant first.