Have you tried a few of those "Your mother..." jokes? ;)

Timing is crucial with this one, but pick up a rock and throw it just past someones torso and say, "Wow, what a fatass, shit! So and so's got his/her own orbit!"

... this doesn't sound as funny in text, but I promise I've got laughs out of people when I've done it.

Also, be careful where you throw the rock. This is not a joke to have when you're waking drunk through a parking lot of luxury cars.

If your a girl

Other Girl: I'm straight, unlike you!

You: Damn straight, washboard.

You look from a distance, (insert a person's name). You step close, shit on the ground.

Ok, not exactly "clean", but eh...

Brother: you're such a gay fag you cunt

punch brother

PROBLEM SOLVED

Brother: i'M TELLING MOM.

You: Tell her what? You're too weak to solve your own problems?

Younger Brother: HAHA, YOU GOT A SMALL DICK

You: Well I inherit traits from dad, so if I got a small one, yours is smaller

You: you're mom is so ________________!

Brother: We have the same mom.....

You: you're adopted

Person: You're so weak and small bro!

You: Well then turns out you're girlfriend is has a loli complex.

(Mostly for Japanese people)

Person: You're so ugly and blah blah blah!

You: Dude, I've seen your family, you shouldn't be talking.

Person: You're gay!

You: Um... are you flirting with me? I don't swing that way.

"Awww sweet" always does the trick. Boys hate being called sweet.