We trade Damien for the virus. That is remarkably ruthless and cold blooded. I approve.

Malcolm

Felicity: Barry!
The Flash: Thank you, Felicity, you just outed my secret identity to a super villain. No offense.
Malcolm: None taken.

There is no greater birth than the one you are about to take on, the annihilation of one's home.

Ra's al Ghul

Felicity: I can't believe he's gonna marry her.
Malcolm: You should worry more about getting out of here alive.
Ray: Is that even a remote possibility?
Laurel: Oliver would never let that happen.
Diggle: He let this happen.

Felicity: Hey Oliver! What's going on?
Oliver: If any of you speak, we're all going to die.
Felicity: What?
Oliver: I need you to trust me.

Thea: Jason, I have a '67 Mustang that need a little work on it. Someone said you were the guy to see.
Roy: You came to the right place.

Oliver: Malcolm, we need help.
Malcom: By all accounts, you were too good at allying yourself with Ra's and I don't think I carry much credibility with them.

Diggle: There's only one thing left of him now.
Laurel: And what's that?
Diggle: Us.
Thea: Gone but not forgotten.

We thought that Oliver was just giving up his life to Ra's, but he gave up his soul.

Felicity

Laurel: If anything happens with Nyssa, let me handle it on my own.
Diggle: Laurel, we're talking about the League of Assassins.
Laurel: I know that. I just...Oliver. You were closer to him than any two people I have ever known. You shouldn't have to...
Diggle: Fight him? Kill him? It's not going to come to that. Look, I'm with Felicity. There is nothing that Ra's al Ghul can do that can turn Oliver against the people he loves.

Diggle: And since when is Ra's' daughter someone we stick our necks out for, Laurel?
Laurel: I know you're furious with Ra's for what he's done with Oliver. We all are. But Nyssa. She saved my sister's life. She gave her a home. She's a good person in spite of everything that she grew up with. And the last time that I checked, protecting good people? That's what we do.

Felicity: If you're going to keep going out into the field, we should really design you some sort of...
Diggle: Do not say costume.
Felicity: OK...identity concealment.

Arrow Season 3 Quotes

Diggle: You love her. You even told her so.
Oliver: I was trying to fool Slade.
Diggle: Yes. Except now the only person you're fooling is yourself.

Keep this up and there will be two kinds of criminals left in Starling City. The ones we put away and the ones running scared.

Diggle