Marcus was here, I took a shower, so obviously we're secret lovers.

Joan

Lack of witnesses won't be a problem -- they're us.

Sherlock

I was mistaken. You don't know what my partner looks like naked.

Sherlock

Gregson: Where is Sherlock?
Bell: He was out with some friends. I sent a radio car to get him.
Gregson: [dubiously] Since when does he have friends?
Joan: These are more 'exercise partners'...

Mason: So, why do you care? I'm just saying, he was a bad guy, now he's dead. You should go see a movie or something.
Joan: The people who killed him also killed his bodyguard and the valet who was getting his car.
Sherlock: And even if there were no innocent victims, no murder should go unsolved, and no murderer should walk free. To think otherwise is to descend into a pit of moral relativism.

There are three surviving Holmes men, and you've sampled the carnal wares of one. Two would be a pattern.

Sherlock

You think the State of New York took out a hit on a Russian oligarch?!

Bell

Bell: Is *anything* this kid's doing legal?
Sherlock: Define 'legal.'

I could have sworn I had that statue removed!

Morland [regarding Sherlock]

Well, you're lying, so I'll just have to investigate the matter myself.

Sherlock

Joan: A woman did this to you.
Sherlock: ...a highly-trained woman.

Joan: Were you two in a fight, or were you having sex?
Sherlock: The two aren't mutually exclusive...

Elementary Quotes

Holmes: Why do you suppose you hate your job so much?
Watson: I don't hate my job.
Holmes: You have two alarm clocks. No one with two alarm clocks loves their job. Two alarm clocks mean it's a chore for you to get up in the morning.

Watson: How do you do it, guess things?
Sherlock: I observe and then I deduce.
Watson: How did you know I was a doctor, you said you could tell from my hands.
Sherlock: Hand, singular. It was soft no calluses.
Watson: How did you know my father had an affair?
Sherlock: Google. Not everything is deducible.