I have a notebook of funny quotes from over the past 2 years, but could only find few that actually seemed funny and not just inside jokes.
Malcolm in the Middle
"Is this a vacuum I see before me?" -Malcolm, doing a Shakespeare impression
"Mom, you took my skateboard, but I know you're sorry." -Reese
The rest are all from the Draco Trilogy by Cassandra Claire. Very hilarious.
Draco Sinister, Part II
"I'm the shrewd, underhanded one. I come up with the cunning plans around here, not you. You wouldn't know a cunning plan if it painted itself blue and danced naked on a harpsichord singing, 'Cunning plans are here again'!" -Draco
"Goddamn it! I can't believe I fell for that! 'Here, catch!' That's the oldest trick in the book, right up there with 'Look out behind you!'" -Draco
"Sometimes I'm wrong. Of course, sometimes the sky turns orange and the Earth starts revolving backwards, but, you know..." -Draco
"You're about as useless as a condom machine in the Vatican." -Draco
"I can imagine some pretty bad things. Come on, I've seen Severus Snape's pajamas. Nothing can terrify me." -Draco
"We can hang out. Tell jokes. Wait for the apocalypse." -Draco
"Did we leave anyone at home, or did everyone come to the let's-get-killed party?" -Draco
"You're right, Weasley. She found me, I killed her, and then I decided to come and tell you all about it because I hadn't yet reached my personal abuse quota for the day and I thought you could help me fill it." -Draco
"It was a medical procedure. A medical procedure that just happens to look a lot like necking." -Harry
"Study? And suck all the fun out of being young and stupid?" -Harry
"Come on, this is Harry Potter we're talking about. He faces danger every morning like most people face bacon and eggs and toast, and I'm suddenly...very hungry." -Ron
"'I'm Draco Malfoy, and this is my impression of a Completely Bonkers Psychopath.'...Come on, he was totally evil. Did you see his outfit?!" -Ron
Draco: I did have a plan. But there was a tiny flaw in that plan.
Harry: Which was?
Draco: It was bollocks.
Sirius: Have you been drinking? At a time like this?
Draco: Well, excuse me, Mister 'I spent the sixties in an Electric-Kool-Aid funky-Satan groove.
Sirius: It was the early seventies, and you should know better.
Slytherin: Do you know what I have planned?
Draco: I was hoping for poker, but I'll bet that it's not that. Ritual killing? Human sacrifice? Pre-ordained deathfest? The old standards, I figured.
Slytherin: Is that what you would enjoy, Draco?
Draco: Actually, I was hoping we could start a little smaller. I've got an idea. We could get sushi and not pay.
Lupin: For your information, I lead a rich and varied social life.
Sirius: Oh, I know. Every night it's Wizard Jeopardy followed by reading all your back issues of Arithmancer's Weekly, and a cup of hot cocoa. Look out girls, this one can't be tamed.
Harry: I think I speak of us all when I say 'eewww'.
Ron: I'll see your ewww and raise you a bleeargh.
Draco Veritas, Part III
"When life gives you lemons, make lemonade, and then throw it in the face of the person who gave you the lemons until they give you the oranges you originally asked for." -Draco
"All right, how's this for a plan. We pick the lock on the infirmary door with a cucumber, escape from school, sneak into the crowded streets of Knockturn Alley while carrying our bell collection, hide in the shadow of a nearby Death Eater, wait 'til he takes us to Voldemort, then - bam! We steal his trousers." -Draco