Sheldon: No, the best organism for human beings to merge with is the lichen itself. That way, you'd be human, fungus, and algae. Triple threat. Like three-bean salad.
Leonard: Give me one circumstance in which that would be useful.
Sheldon: All right, picture this, a beautiful outdoor concert. Now, as a human, I appreciate Beethoven. As a fungus, I have a terrific view, growing out of a towering maple tree. And no thank you, expensive concessions. Because as an algae, I'll just snack on this sunlight.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Barry Kripke: Yes, yes, yes. He's a jolly good fellow. What time do the strippers arrive?

Stuart: Okay, I'll go. Howard, when I think about you and Bernadette starting this wonderful life together, I can't help but get a little choked up. I mean, look at you. You have everything. Look at me. I'm 37. I sleep in the back of a comic book store, and I have the bone density of an 80-year-old man. To Howard.

Raj: When I moved to America I was pretty lonely, but when I met Howard my life changed because we could be lonely together.