I believe TheVyper did this in the Oblivion forum a long time ago, and I think Skyrim needs it as well:

This is where you post funny replies you find yourself mumbling to NPCs while sitting in front of your computer, TV, etc.

My examples:

Lydia: "I am sworn to carry your burdens."
Me: "Uh... well, I failed the English test. My girlfriend is mad at me. Uhm... my parents are drinking, and my little brother gets bullied at school... OH, you mean my equipment. Yeah, here you go.."

Guard: "I used to be an adventurer like you..."
Me: "... then Todd Howard decided you and the other 500 city guards should all take arrows in your knees, yeah, that's great."

Merchant: "I've got some fine armour right here."
Me: "No thanks, I'm Arch-Mage."
Merchant: "Need anything?"
Me: "LOOK AT MY ROBE, I'M THE ARCH-MAGE."
Merchant: "Got something for just about everybody here."
Me: "Got any magicka potions?"
Guard 1: "No lollygaggin'."
Me: "I'm not lollygagging, I'm just asking for a magicka po..."
Guard 2: "No lollygaggin'."
*Fireball*

What are yours?

Mirmulnir: Dovahkiin! Noooooooooo!

Me: *starts humming* Trololololo lololo lololoooo lololololoooo! ~

Most of mine would be censored. These NPC's are really stupid.

Sigurd: "I work for Belethor at the General Goods store."
Me (benevolent): "I know, Belethor is a good man."
___

Old woman: "Come to chat with an old woman, hmmm? Do your good deed for the day?"
Me (aggressive): "Who the f' is talking to you???"
___

Battleborn: "Do you know what is wrong with Skyrim these days?"
Me (depressed): "...you..."

Girl: "I work with my mother, to sell fruits and vegetables. It's fun most days, bu.."

Me: *crunch* warhammer to head. "Shut up stupid girl"



Spectral Assassin (with the Roger Moore sounding voice) :"Have you heard the tale of Mathieu Bellamont, and the great treachery of Cheydinhal? Kill a boy's mother, and vengeance festers in the son..."

Me: Yes... yes I have. You tell me every time I summon you. Now zip it.

I always (almost invoulentary) say out loud "Myyy sweeetroool!" in a mock-crying voice when asked if it as stolen.

I make it a point to copy everything guards say and try to say it in the same accent x)

I'm trying this - it sounds fun.

Not as interesting or specific but when someone says something that you don't like (or you just don't like the NPC)
"Shut. Up."

Titles are bolded.
Dragons
Guard: What is it? Dragons?
Me: No. That is the gas.

Arrow in the Knee?
Guard: I used to be an adventurer like you then I took an arrow in the knee.
Me: You wanna take another?
Guard: No lollygaggin'
Me: FUS RO DAH!

Maybe I'm Dragonborn....
Guard/Person: Maybe I'm Dragonborn, I just don't know it yet.
Me: Maybe you're [censored], you just don't know it yet.

Never Should Have Come Here!
Enemy (mostly Bandits): Never should have come here!
Me: Ummmmm you attacked me!

Avenicci, Avenicci, Avenicci.
Adrianne Avenicci: I don't claim to be the best blacksmith in Whiterun, Eurland Gray Mane has that honor. All I ask for is a fair chance.
Me: Uh huh. I didn't say you were the best blacksmith, that would be stupid. I'll come back tomorrow.
[Next day]
Adrianne Avenicci: I don't claim to be the best blacksmith in Whiterun, Eurland Gray Mane has that honor. All I ask for is a fair chance.
Me: Can you shut up and let me browse your products? I have heard this a MILLION TIMES. Actually I'm kind of glad you are not the best blacksmith.

Sweetroll
Guard: Let me guess. Someone stole your sweetroll?
Me: Let ME guess. Someone stole your life?

Flame and Burn
Someone: Don't burn something down with that fire. (or something like that)
Me: If I could!

The SecARITY in Whiterun
Stupid guy at the Bannered Mare: The secARITY in Whiterun iz TURRible. SHAMEful iz wut it iz.
Me: The security of your house is terrible. Shameful is what it is. Or do you even have a house?

I work for Belethor, at the general goods store.
Sigurd (hope I got his name right): I work for Belethor, at the general goods store.
Me: Great!
[Moments later, after we just passed by each other]
Sigurd: I work for Belethor, at the general goods store.
Me: Got it!
[Next day, after ientaculum]
Sigurd: I work for Belethor, at the general goods store.
Me: Alright, yeah, I know. Really, you can stop saying it.
(Presses A button)
Sigurd: I work for Belethor, at the general goods store.
[Next day, after cena]
Sigurd: I work for Belethor, at the general goods store.
Me: ........0_0
[Next day, after vesperna]
Sigurd: I work for Belethor, at the general goods store.
Me: Okay, aren't you supposed to be at your home.......sleeping?
[Next day, after prandium]
Sigurd: I work for Belethor, at the general goods store.
Me: By the way, why aren't you there at his store? You say you work there, but it is the middle of the day and you're not there working for him. Therefore you DON'T work for Belethor at the general goods store!
Sigurd: ..............I work for Belethor, at the general goods store.

You know what's wrong with Skyrim these days?
No, but I know a forum you can go to and get an earful.

guard "what is it dragons?"

me "nope horkers giant fire breathing man eating horkers"

ignorant carriage driver "ever been to markarth? some say it was built by the dwarves i dont believe a word of it tho"

me" okay genius what other culture do you know of that builds giant killer machines out of that brassy dwarven metal and builds cities where everything is either made of stone or that same brassy metal and the steam machines sir the steam machines! you know what i hope someone steals your sweetroll next time you want one and then throws a dwarven spider right at your ugly dumb face!" <-- no joke i was ticked first time i hear mister whiterun carriage driver idiot speak

Random NPC: "That spell looks dangerous..."

Me: "Not at all moron. It's called candlelight." or "That's not a spell, I'm just happy to see you!"

Guard: "Can you summon me up a warm bed?"

Me: "I wish I could. I'll research that." That is a spell I would like to be able to make/have.

Oh, I tend to do this with many games.

Usually in Skyrim I find myself saying "Shut the F up" when an npc is just going on and on about something...

After playing Oblivion for so long, I would always say "I'll take that, and thank you very much."

"Anyone else feel like running?"

*raises hand*

Jarl's son in Dragonsreach "Another adventurer here to lick my fathers boot's. Good Job."

MY Female char " Honey if I wanted to toady up to your daddy it wouldn't be his...never mind"

Women in Riften Bar

"I don't have any business with you, so get out of my face"

- ......Da [censored] you just say to me you [censored] ass [censored]?

Hahahahahahahahhaha

Bandit: " I'll gut you like a horker!!!"
Me: (imagining voice actor in sound booth wearing headphones shouting that into microphone) LOL

Godern freeging snot nosed kid in whiterun: "Come to lick my fathers boots...blah blah god job"
Me: " Soon you will pay. For i wield the power of [CONSOLE COMMAND] and I will summon you against your will to any place i choose, and command you to die over and over again.


Lydia: "I am sworn to carry your burdens."
Me: "you smug biatch. it must be so bad for you, to take these gifts of [FULL EBONY ARMOR] and [ENCHANTED DAEDRIC SWORD] and priceless artifact shield of Iysgramor. Maybe i will go find Kharjo and have him follow me around. He doesnt complain so much.

Maven Blackbriar: "anything that comes out of my smug pretentious face"
Me: sunnofabish Bethesda, why would you not write in an alternative story branch so I can kill this hag. And then, OMG the empire puts her in place as (spoiler)!!! I will burn your beehives to the ground in every new game I start, it is the only thing I can do to rage against VITAL NPC overlords.

I lol'd. "To the hills!"

At the college....

Dunmer lady giving me the tour of campus: "here are the dormitories, inside the students rest and study, so please keep your voice down inside"(or something similar to that anyway)
Me: (goes inside dormitory) FUS...RO DAH!!

"Maybe I'm dragonborn, I just don't know it yet.
me: I beg to differ- Yol Toor Shul!(at the clouds)

"you've got business here, good. Otherwise, hit the road"
Me: Ok, I'll hit the road....with your scaly nose. repeatedly

Haha, that's a good one. xD

Tolfdir: "This is simply fascinating."
Me: "Yeah... we've got a huge, unknown, potentially extremely dangerous magical item right here, a few kilometres of rock above our heads and about a dozen Draugr on our tail. I agree. This architecture is simply fascinating..."

Brelyna:I'm a Mage, not a pawn-broker you know?

Me:Ha! You said porm!

Woman who wants to get wabberjacked: "Wabberjack Wabberjack Wabberjack Wabberjack Wabberjack"
Me: "Oohhh nnoooooooooooooooo, not you ..."

I do love her though.

"Got to keep my eyes open. Damned dragons could swoop down at any time!"
Yes. Swooping is bad.

"Don't suppose you'd enchant my sword?"
Enchantment!

"Is that fur coming out of your ears?"
(Khajiit character) Yes, and everywhere else too. Real pain in the tail let me tell you.

"Who did you have to kill to get that blade?" (Guard comment about Mehrune's Razor).