"Sorry boss, I can't come in today, I seem to have misplaced my liver."

Me: "Mr Peterson. I can't come into work today."

Him: "Well thats unfortunate. Can I ask ya why not?"

1) Me: "I have scurvy. They've tied me down and are feeding me orange juice intravenously."

2) Me: "Someone has died."
Him: "Oh I'm so sorry! Who was it?"
Me: "I don't know but he's in my kitchen."

3) Me: "I came down with a minor case of spontaneous dental liquification and count-choculitous."

4) Me: "I have things to see and people to do and my dislexia is acting up!"

And, pushing the boundaries just slightly:

5) Me: "Turrets syndrome bitch!"

6) Me: "I'm exhausted and I can barely move. I was nerdgasming all night long on The Escapist!"

Me - Sorry Boss, I'm to ill to come into work today
Boss- May I ask why?
Me - No

Me - Sorry Boss I can't get to work today
Boss- What's wrong with you?
Me - Just can't be bothered

Me - *cough* Urgh, Sir I'm to ill to come into work today
Boss- What's the matter with you
Me - I have infected diarrhea

Me: "Ah ahd a twoke."
Boss: "What?"
Me: "Ah ahd a twoke."
Boss: "I can't understand what you're saying.
(I hand the phone off to someone else)
Someone Else: "He had a stroke and won't be back to work for a while."

The conversation is fake, but the excuse was real. I just had someone else make the call. It would be kind of hard to follow that one up if you faked it.

Khedive Rex:
2) Me: "Someone has died."
Him: "Oh I'm so sorry! Who was it?"
Me: "I don't know but he's in my kitchen."

That's so brilliant I might actually use it.

I can't come in, I have a bone in my foot
I can't come in, i have perferated earlobes

"Women Problems"

If you're a man, then you just say that the problem is with the woman... but its still your problem...

I like to think that Ferris Buller said it best in "Ferris Bullers Day Off"...

I was reading Somethingawful's Comedy Goldmine a while back, and some one actually called into work saying he couldn't come in because he hated the smell of peaches.

It turns out, he said this while he was sleeping. He actually managed to dial his cell and call into work while sleeping. He was shocked when he woke up, and went to work because they all weren't expecting him. He had to check his cell phone call log to find out the truth.

The voices in my head said it was important that I stay home and clean the guns.

-- OR --

I have gluteal glaucoma. I can't see my ass coming to work today.

"My twitch is back and I don't want to break anything."

"Last night I had a party and I woke up with a stranger in my bed."

"The city is paving my street and I can't leave!"

"My home is flooded and I am currently clinging to my ceiling fan."

"The dog ate my car keys. We're going to hitchhike to the vet."

"I ate a 'do not eat' pack in my shoebox."

"Today's Friday the Thirteenth. I don't want to die, boss."

"Don't pay the ransom - I escaped!"

"My garage door opener is busted and I'm too iron-deficient to open the garage door." - Actually used by my childhod babysitter.

"My front door spontaneously combusted."

"My agoraphobia is kicking in and I am afraid to drive today."

"There has been an urgent family emergency, which I can't talk about lest I endanger any innocent bystanders."

"My phone bill went unpaid and I have to stay home to pay it..." From a slightly-drunk peer, calling from his home phone.

"I seem to have an extremly bad case of green thumb. My doctor say I only have a month to live."
"I've decided to tell you I hate you, and thought you would be mad at me."
"I am just... too... whats the word? Apafettic? Eh, I don't care."

"My igloo is melting."

(Okay, I've never actually called in sick to work when I wasn't. XD;)

Gxas:
My friend used to be in a huge raiding guild in WoW (no, this isn't a sick story) and was always forced to raid. At times when he didn't want to, he would say, "Sorry, there's a bear in my room," and then sign off. I've taken to using it a lot when I don't want to do something.

OOOH I like that one. Mind if I use it?

Bored Tomatoe:
"I was sexually assaulted by a monkey"

Might wanna use that one a couple times too.

On the humorous side of excuses, my favorites would be:
"There are complications with my period" (note, I'm a dude...)
"I have a fresh surgical scar that wasn't there when I went to bed"
"I have a bad case of lag, my FPS drops any lower the doc says I could crash"
"I'm suffering from a severe case of priapism and I'm not sure if it's contagious"
"I'm the god damned Batman"

Useful excuses that they'll never call upon you to prove
"My athletic cup failed at [insert sport here] and I'm awaiting x-rays to see if there's permanent damage" (good for multiple days off)
"I found a lump in my [insert body part here] and want to get it checked out"
"I need to bail my [insert family member here] out of jail, he/she was busted last night for [insert crime here]"

The only excuse I've used for the last 2 years
"I'm the god damned boss" (only works when, like me, you're in one of the top positions on the totem pole)

"A friend of mine decided to go to school when they didn't want to once, and was later raped to death by a coyote in a separate incident."

My ebola is really acting up today.

I used this one many times to get outta work

"I got a bug, I think it's a one day bug. My (insert random family member) gave it to me but I should be good by tomorrow"

I just found out I'm under eighteen. My birthday is tomorrow though, so I'll see you then.

Slycne:

1. Always call your boss to tell them you're not coming in; never e-mail. "An e-mail just seems really fake," says Marcus. She notes that at some companies your boss might say, "Great: you're on e-mail. Just work from home today," which negates the purpose of taking your elective sick day. A telephone call comes off as a little more truthful and a little more urgent. When you call, try to time it so that you can leave a voicemail -- talking about the fact that you're sick opens it up to the possibility of follow-up questions and debate.

2. Don't be too specific. "Say 'I have a migrane' or 'I have food poisoning,' but don't go into details," says Marcus. "A lot of people get caught up in the details of the lie and feel like they have to specify what their symptoms are and such. But the more you talk, the faker it sounds. If you have the stomach flu, you're probably too busy barfing to answer a lot of questions about your condition."

3. Food poisoning is a good fake ailment. Marcus points out that "It's quick; it lasts a day; people get grossed out by it; and it's happened to them. So food poisoning is the way to go. Plus it's really non-specific. It doesn't say anything about a recurring condition that's going to happen again. It's a fluke. No one knows why it happened or what it was that they ate, so it's a really good mystery disease."

4. Don't post your exploits from your sick day on Facebook. Remember this story? Don't get caught in your lie by putting too much information where people can find it. "As people have things like more and more social networking sites, or you have a blog that people in your work know about, you need to be really really careful about indicting in any way what you were doing on your day off -- because you will get busted," says Marcus.

5. Don't come in with a sudden tan or a brand new wardrobe the next day. "Keep your head down and do your work," she says. "People are always a little skeptical, and you have to just pretend like you really were at home sleeping all day."

6. Pick a random Tuesday or Wednesday for your fake illness. At a lot of companies, there are mysterious sick waves on the day after a long weekend or on a really beautiful day in the summer. You can get away with that once in a while, but if you only come down with the flu on really beautiful Friday afternoons in the summer, everyone will be on to you. Taking off a day in the middle of the week will also make it less likely that you have 400 emails to sort through all at once when you come back from your elongated holiday.

http://www.asylum.com/2008/09/02/how-to-take-a-sick-day-when-youre-not-sick/

I disagree with point number 2. You can give details, you just need to make it realistic.

"I Have conteages explosive diariah and don't want to... *Explosion sound effect from you computer o W/E* oops, got to go, bye!"
*click*

your wife gave me the AIDS

Digestive problems. Bad enough to warrant a sick day, disgusting enough not to warrant questions and recoverable enough that you can come back the next day without question.

This is a good way to call in sick, though you can only use it once.

"Uh, I can't come in to work today..."
"Why is that, then?"
"Someone has died."
"Who?"
"I don't know, but they're in my kitchen."
"You take all the time you need."

Why aren't I coming in? Because fuck you, that's why!

Chances are you'll never have to go back there after that.

One which I've used before was simply call up the place in question (in my case it was school) and explain to them that I'm not going to be in, when they ask why I merely say 'religious reasons' in a hushed tone (as if it's something personal or sensitive, you could replace religious reasons with 'family emergancy' if they know you're not religious).

They never seem to ask any questions beond that point.

Just for giggles though, here's another:
Me- Hello? I won't be in today, my aunt died and it's her funeral today.
Them- Wait a minute, you've been to an aunt's funeral 3 times in the last week, how does that work?
Me- Er...my Dad has 12 sisters, 3 down, 9 to go.

I had the bear AIDS

He came down with a mild case of dead.

"My dog recently ate himself when i forgot to feed him. I'm going to spend the day trying to graft a cat butt on to him."
(only works if youre a psychopath)

John(me): Dude, I cant go to work.
Boss: Why?
John: Theres a maroon coloured substance dripping from my ears.

Pretty great excuse, always works.

my phone is broken and i have to fix it

My XBOX broke a day out of warranty, I am suicidal.

"I am dead."
"You called me at a real bad time...*excessive toilet flushing*-"Baaaaaaad time."
"I'm sorry I can't come into work today, because, as it is plain to see I am at the game, standing in front of you at the restroom queue."

Blood in my stool or urine

mine vomit all over your boss. make sure you had bratwurst and cottage cheese so it looks like you ate some weird crud. works every time also your boss might also get a day off

I can't come in today, I'm negotiating for world peace.