Sheldon: Oh what fun. Like hippies at a love-in.
Leonard: Just sit here.
Sheldon: Right on man, right on.

Leonard: Still arguing which is the best CSI?
Howard: We agreed they all have their merits.

I'm still not adjusted to how SyFy spells their name now. S-Y-F-Y... that's siffy.

Sheldon: I'm not aware of the acronym KMN.
Leonard: From the context we think it means 'kill me now.'

Leonard: How do you get an entire lecture hall to flip you off at the same time?
Howard: Apparently if you're Sheldon all you have to do is turn your back.

Penny: What if I got him to apologize and promise to behave?
Leonard: Then I guess we would let him back on the app team and while we're doing that, you can take an aerial tour of L.A. on your flying pig.

Leonard: It's what we do. We give each other a hard time. Hey, Sheldon, you look like a praying mantis.
Sheldon: That was very hurtful.

You actually want to deceive your father with some sort of sham, playacting and kissing? Because I'm good with that.

Sheldon: And here's where we are -- the runts in a large litter unlikely to ever reach the nourishing teats of Indiana Jones.
Leonard: So it's good we stopped for dinner.

Leonard: Hi. I'm Leonard. You are beautiful. You pop, sparkle and buzz electric. I'm going to pick you up at eight, show you a night you will never forget.
Raj: Where are we going?

Raj: Woh, woh, woh! I don't want to speak to the FBI.
Leonard: Why not?
Raj: I'm brown and I talk funny.

Leonard: You put moths in my food!?
Sheldon: For science.

TBBT Quotes

Sheldon [to Kripke]: Also, I am given to understand that your mother is overweight.
Raj: Oh, snap.
Sheldon: Now of course, if that is the result of a glandular condition and not sloth and gluttony then I withdraw that comment.

How is "doable" anything but a compliment?

Wolowitz