Sheldon: You need to remove that chair from the building. It’s a health hazard.
Penny: Okay, relax. I took off the slipcovers, had them dry-cleaned and then fumigated the cushions.
Sheldon: Really?
Penny: Yeah. It's cleaner than my couch. Found half a Hot Pocket in there.
Sheldon: It certainly looks okay. Has a strong toxic chemical smell. That's reassuring.

Sheldon: Under my authority as a self-appointed member of the Centers for Disease Control street team, these premises are condemned. (Penny tries to close the door) As a man with a keen sense of style, I must tell you, that chair does not work with the room.

Sheldon: I was hoping she might listen to you about the dangers of owning unhygienic furniture.
Amy: For general educational purposes, or has she acquired a bar stool dipped in cholera?
Sheldon: Cholera is water-borne. You're mocking me.

Amy: Will you listen to me play my harp now?
Sheldon: No. I dislike the sound of the harp. Its overuse in classic television sitcoms always makes me think I'm going to experience an episode from my past.

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

Sheldon: If there is ever a church of Sheldon, it started here.

Sheldon: Whenever you're ready, AT&T!

Sheldon: Geology isn't a real science!

Sheldon: If I could I would, but I can't so I shan't.

Sheldon: If it's good enough for Kirk, Crunch, and Kangaroo it's good enough for me.

Sheldon: Now, knowing Penny, the obvious answer is, they engaged in coitus. But, since that's what it looked like, we can rule that out. Let's put on our thinking cap, shall we? (Mimes doing so) Raj is from India, a tropical country. Third world hygiene. Parasitic infections are common, such as pinworms. The procedure for diagnosing pinworms is to wait until the subject is asleep, and the worms crawl out of the rectum for air. (Leonard spits out his food) Yes, just like that. Penny could have been inspecting Raj's anal region for parasites. Oh, boy. That's a true blue friend.
Leonard: They slept together, Sherlock.
Sheldon: No, you weren't listening. She said, it's not what it looks like.
Leonard: She lied.
Sheldon: Oh. Well don't I look silly sitting here wearing this?

Sheldon: That sounds like sarcasm, but I'm going to disregard it, because I have an agenda. Paintball. Specifically, the interdepartmental tournament this weekend. Now, in order to function better as a fighting unit, I thought we should establish a chain of command. Now, it goes without saying that I would outrank the three of you, but the question remains, by how much? Now, I don't see me as some four-star general, back at HQ riding a desk and playing golf with the Secretary of Defense. But I also can't be Sergeant Cooper, because that might lead you to think of me as just a regular Joe. This might take some thought. As you were.

Leonard: Do we really have to wear this camouflage crap to play paintball?
Sheldon: Who said that? Leonard, I can hear your voice, but I can't see you.

Sheldon: Okay, here we go. This is us here. To the south is Professor Loomis and the Geology Department. According to their Twitter feed, they're out of sunblock, which means they'll have to hug the tree line or risk melanoma. That's our edge. All we have to do is move quickly over this ridge, the rock-worshipping pasty-faced bastards won't know what hit them. All right, let's move out.

Leonard: You know what, guys, I'm not in the mood for paintball. What do you say we just bag it?
Howard: Fine with me.
Raj: Sure, whatever.
Sheldon: You can't quit. That’s a court-martial offense. That's punishable by … You can't quit.