Frank: Erin's taking a look.
Lenny: That's good.
Frank: I didn't ask her to over look, just look.

Erin: Do you believe him?
Frank: Yeah, I think I do.
Erin: That “think” kind of waters it down.

Baker: Something occurred to me today. You are the only member of this department to have presided over a line of duty death both as the commissioner and as a fallen officer's father.
Frank: Meaning?
Baker: That maybe you should hold off meeting with the mayor until...
Frank: Until I'm calm. That'll be never.

I would like you to put on an NYPD uniform, and 20 lbs. of equipment, and a gun belt, and run up six flights of stairs to save a woman who is being beaten by her boyfriend, and then, I would like you to be raked over the coals for your effort. And then, when you have that frame of reference, maybe we can talk.

Part of what we love most about the job is that there's always a fresh pain in the ass around the corner.

Kelly: It gets resolved the way most disputes do. Nobody gets everything they want.
Frank: Perps do. It's free money.
Kelly: It's nickels on the dollar.
Frank: They're still free nickels.

Gee, I must have missed the part that was underlined, italicized, and highlighted.

Of whom much is given, much is expected.

Terrorists have weaponized your product, Mr. Post, as sure as if it were an airliner or a rented box truck, and you're going to sit here and tell me that people's privacy deserves your protection but their lives do not?

I know it was like throwing pebbles but sometimes if pebbles is all you've got that's what you throw.

Frank: It's never really over is it. The best you can hope for is a lull before the next bad thing.
Sid: Yeah, well, it keeps us on our toes.
Frank: Right now my toes hurt, Sid.

Frank: At least I know one wedding present you're getting, your choice of precincts to transfer to.
Erin: Oh gee, Dad, every bride's dream.