Not every insult requires a response.

Jimmy

Margaret: Are you in the habit of toying with women, Mr. Sleater?
Owen: I wouldn't call it a habit.

Jimmy: Think I can't play this game?
Nucky: I don't think you even know the rules.

Richard: Would you fight for me?
Jimmy: Of course I would, right down to the last bullet.
Richard: Then let's go to work.

Is this to be our life?

Margaret

Jimmy: Alright, Mom.
Gillian: Alright, leave me alone, or alright, I understand what needs to be done.
Jimmy: Both.

A bit cheeky, isn't he?

Margaret on Owen

I lost whatever I thought love was.

Richard

I didn't spend my life getting groped by a bunch of drunks to wind up in a goddamn poor house.

Gillian

Mickey: From the tiny acorn grows the mighty elk.
Jimmy: If you had a brain, you'd be dangerous.

Nucky: I keep my promises, James, and I'll make you one now: I will ruin you, all of you.

Nucky: How's Torrio handling the competition?
Capone: We're killing them.