(Shamelessly stolen from an imgur dump, but I felt like it belongs here)

Edit:

Since so many of you suggested additions, I'm just going to list them all in one place. Let's create a community-made enzycrapedia of shit-related terms and phrases!

Transcription of the image in case the picture disappears:

• Dogshit: Very poor quality

• Bullshit: Not true

• Horseshit: Nonsense

• Apeshit: rambunctious

• Batshit: insane

• Chickenshit: coward

• Ratshit: poor quality

• No shit: obviously (also sometimes "No shit, Sherlock!" as an exclamation)

• Holy shit: mind blowing / unbelievable

• Hot shit: very good

• Dipshit: a total dumbass

• Tuff shit: take it or leave it. (correct spelling would be "tough shit")

• Jack shit: nothing

• The shit: perfection

More shit:

• Cut the shit: knock it off.

• Are you shitting me: are you serious.

• This shit is bananas: this is crazy.

• That’s my shit: I really like that.

• I dig that shit: I love it

• Shit!: An exclamation of discontent. See also: fuck.

• I shit myself: I pooped my pants.

• Shit-Hawk: unpleasant person

• For shits and giggles: Doing something silly for no particular reason

• Shit a brick: to be scared

• Scared shitless: being really scared

• Shitstain: someone trashy or worthless

• Shit for brains: stupid

• Shit sandwich: a shitty situation

• Shithead: a shitty person

• Shithole: a shitty place

• Piece of shit: a shitty thing

• Deep shit: a meaningful revelation

• To be up shit creek (without a paddle): to be in deep trouble

• To be full of shit: constantly lying

• Shit Stirrer: someone who deliberately causes problems/arguments

• Get your shit together: to organize stuff properly (alternatively; to calm down)

• Losing your shit: freaking out

• To [do] the shit out of something: doing something in an excellent way

• I don't give a shit: I don't care

• When shit hits the fan: when an already bad situation suddenly becomes worse

• Shit happens: bad things happen and you can't do anything about it

• Shit just got real: Something dangerous is happening right now

• Does a bear shit in the woods?: Isn't it obvious?

• Eat shit: To fall on your face

• Shit-eating grin: a smug and condescending expression

• Who shit in your cereal?: Who ruined your day/mood?

• (To watch the) Shitshow: watching utter chaos unfold without intervening

• A metric shit ton: a lot

• Shit on a Shingle: a dish consisting of a cream sauce with meat in it poured over toast

• Nuttier than squirrel shit: being crazy

• Shitstorm: a stressful, chaotic situation

• You don't know shit: you're clueless

• Don’t shit where you eat: Don’t date a work colleague

• The shits: diarrhea

• My shit: my stuff

• Shitter: toilet

• You are shit: you're worthless

• You are not shit: reassuring that you're NOT worthless

• You ain't shit: you're worse than worthless

Thanks and credit to: Poopmeister, Wogi, protist, cloudy1999, lambchop and ToRa