Penny: Oh, my God, I screwed up everything. I hurt Leonard, I hurt Raj, I mean, what is wrong with me? I feel like two totally different people, Dr. Jekyll and Mrs. Whore.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

Leonard: Well, uh, okay, um, I dont want to get back together with Penny. We tried it, it was crazy, it didn't work, but I can't deal with the fact that she slept with my friend Raj. And then I find out that Raj's sister Priya, who I've been going out with for eight months, is moving back to India. So I'm just completely confused and alone.
Beverly Hofstadter: I understand.
Leonard: Got any advice?
Beverly Hofstadter: Yes. Buck up.
Leonard: Excuse me. You're a world-renowned expert in parenting and child development, and all you've got is buck up?
Beverly Hofstadter: Sorry. Buck up, sissy pants.

Sheldon: For the record, I do have genitals. They're functional and aesthetically pleasing.

Amy: A guest in my trundle bed and a boy at my door. I wish I could tell thirteen-year-old me it does get better.