Penny: I mean, who even reads Scientific American.
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Okay, then, how about this. Let's invite everyone over to dinner. It'll be like Ma's feeding us one last time.

Howard

While my brother was getting an STD, I was getting a PhD.

Sheldon

Leonard: And we weren't even watching TV! We were watching Netflix like the kids do!
Penny: Yeah! Is it a comedy? Is it a drama? Nobody knows!

Bernadette: A two-hundred dollar R2D2 is a business expense?
Howard: Oh, Bernie. You're gonna have to sound a lot more confident when we get audited.

Leonard: It comes with paints and it's kind of creative and artistic.
Penny: Okay, did you go to the dirty store, or Michaels?

Penny: See, this is why I've been saying we should keep champagne on ice.
Sheldon: Sarcasm?
Amy: Yes.
Sheldon: That was tricky because when it comes to alcohol she generally means business.

Amy: After a careful evaluation of our relationship. We decided that the time was right to take a step forward.
Leonard: Okay.
Sheldon: Do you want to say it?
Amy: Let's say it together!
Sheldon and Amy: We're getting a turtle!

Excuse me. You better find my husband's mother, because one way or another, we're walking out of here with a dead woman!

Bernadette

Sheldon: If you could wake up tomorrow having gained any one quality or ability, what would it be?
Penny: Well, not to steal from the Bible, but turning water into wine sounds pretty good.

Leonard: I'm telling you, you can't create love in a few hours. Right?
Penny: Careful. You're poking at the whole foundation of The Bachelor.

Amy: I just read about an experiment designed to see if you can make two people fall in love in a matter of hours.
Leonard: That doesn't sound right. My research has shown that it takes three to five years of shameless begging.

TBBT Quotes

Penny: Leonard, sweetheart, you twisted your ankle playing Scrabble.
Leonard: I got a triple word score with a double letter Q. If that's not a time to bust out the Scrabble dance, what's the point of having one?

Given that St. Valentine was a 3rd century Roman priest who was stoned and beheaded, wouldn't a more appropriate celebration of the evening be taking one's steady gal to witness a brutal murder?

Sheldon