He left a boy. He returns a boy-sized hero.

Sheldon

Howard: Attention people of Earth: Tonight, there will be two moons in the sky.

It had weaponized fruit and a puppet. What more do you want?

Leonard

Mmm, the nurse is a woman, so he couldn't talk to her. She had to bring him a Grover puppet so he could point at what hurt.

Leonard

You were right. I had nothing to worry about. That skank's your problem, not mine.

Amy

I'm in her head. Let the dance begin.

Raj

Amy: Looks like something used by Tinker Bell's gynecologist.
Penny: Who I hope for her sake is not Captain Hook.

They left dogs up here in the 60s.

Howard

Sheldon: Flattery will not get you this job, Ms Jensen
Ms. Jensen: It's not flattery, if it's the truth.
Sheldon: Oh, well, thank you. Welcome aboard.

Penny: I'm just a blonde monkey to you, aren't I?
Sheldon: You said it, not me.

Call me a romantic. I like to think your Mark Ruffalo is still out there somewhere.

Sheldon

Stuart: Watch out ladies: a little coffee and cream coming your way.
Raj: In case you didn't follow that, I'm the coffee.

The Big Bang Theory Season 6 Quotes

Amy: Soon my upper lip will be the same fake blonde as my beautiful best friend.
Penny: Hey, this is my natural hair color - Now.

Right now, Howard is staring down on our planet like a Jewish Greek god - "Zuesawitz".

Raj