You know Oliver, somebody once told me that secrets have weight. The more you keep, the harder it is to keep moving.

Oliver: John, I don't want to die down here.
Diggle: So don't, Oliver.

Felicity: Guess what I majored in. Hint - not the secretarial arts!
Oliver: Felicity! If I'm going to be Oliver Queen, CEO, the I cannot very well travel down 18 floors every time you and I need to discuss how we spend out nights.
Felicity: And I love spending the night with you...three...two...one. I worked very hard to get where I am and it wasn't so I could fetch you coffee!
Diggle: Well, it could be worse. My secret identity is his black driver.

Oliver: We're late.
Diggle: The good news is you get to make your dramatic entrance.
Oliver: Oh I'm just glad Oliver Queen has a reputation for showing up late.
Diggle: You know, I've been meaning to tell you it really wears me out no end the way you refer to yourself in the third person like that.

I think you didn't have a problem with Felicity’s performance until she met Barry Allen.

You're like a dope fiend who thinks he can deal with his own addiction by making another addict go straight.

Diggle [to Oliver]

Diggle: What did you want?
Felicity: Is that any way to treat a girl who just walked up six flight of stairs?
Diggle: No, it's not. Welcome.

Besides, Army regulations. A brother never lets a soldier go into battle alone.

Felicity: Where are we going to get our hands on a rare Spanish antiquity?
Diggle: You really have no idea how rich his family is, do you?

I take back every joke I made about you sticking a tracking device in your boot.

Malcolm: John?
Diggle: My friends call me Dig. You? Shouldn't even talk to me.

They need the man in the hood.

Arrow Quotes

Laurel: Helena, you don't have to do this.
Helena: Yes, I do. Because once you let the darkness inside, it never comes out.

Oliver Queen is dead, eventually to be reborn as Ra's al Ghul. For now, only the Arrow, Al Sah-him, shall remain. Al Sah-him, Heir to the Demon.

Ra's al Ghul