Sheldon: Beverly pointed out that I'm experiencing insecurities in my relationship with Amy, in the same way that Leonard and Penny are in their relationship.
Penny: What are you talking about? We're fine.
Sheldon: Yes, you're fine as long as you have a buffer living with you to distract from your marital problems. It used to be me. Now it's Raj and his attack Tribble.

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.

Sheldon: Well, I think it's very nice that you're helping out our friend.
Leonard: I think it's nice that you're taking whatever medication Amy's clearly giving you.

Amy: This isn't about me and Sheldon. This is about Rajesh moving in with Leonard and Penny.
Beverly Hofstadter: Interesting. They've found a need to take yet another roommate. Seems they're avoiding some harsh realities themselves.
Sheldon: I had no idea all our relationships were such a disaster. Boy, you're good.
Beverly Hofstadter: That is the word on the street, dear.

Raj: Maybe moving in was a bad idea. I haven't been here one day, I'm already causing problems.
Penny: You didn't do anything. It's Sheldon.
Leonard: "You didn't do anything.It's Sheldon." That'd make a nice needlepoint pillow.