Sherlock - Season 4

Dr. John Watson: "You didn't kill Mary. Mary died saving your life. It's her choice. No one made her do it, no one could ever make her do anything, but the point is, you did not kill her."
Sherlock Holmes: "In saving my life she conferred a value on it... It is a currency I do not know how to spend."

Faith: "Well... what is the worst thing you could do?"
Culverton Smith: "Tell them your darkest secret. Because... if you tell them, and they decide they'd rather not know, you can't take it back. You can't unsay it. Once you've opened your heart, you can't close it again."

"You're suicidal. You're allowed chips. Trust me. It's about the only perk."

"Taking your own life... Interesting expression. Taking it from who? Once it's over, it's not you who'll miss it. Your own death is something that happens to everybody else. Your life is not your own, keep your hands off it!"

Faith: "Oh... big brother is watching you."
Sherlock: "Literally."

"There must be something comforting about the number three, people always give up after three."

"Stop talking. It makes me aware of your existence."