Awesom-O. The first scene had me in stiches.

BUTTERS
Yep. That's right. He's a real live
robot. He can walk and talk and everything.
You're like the fourth kid I told already.
Well I gotta go Dougie. My robot and
I have stuff to do. Heheh, they're
all so jealous! I'm so glad you came
into my life, AWESOM-O. You're the best
friend a guy could have.
CARTMAN
Yes. You can trust AWESOM-O. In fact,
you should tell AWESOM-O all your most
personal secrets. AWESOM-O will not
make fun of you or tell your secrets
to other people and stuff.
BUTTERS
Hey yeah! Well I can tell you anything,
huh? Well lessee... Well, for one,
I have what's called a heziated colon,
which means I sometime can't control
my sphincter.
CARTMAN
Could be.
BUTTERS
Well, nobody knows it, but sometimes
I poop my pants, so I have to wear a
diaper to school. You okay, AWESOM-O?
CARTMAN
Yes. AWESOM-O is fine. Please go on.
BUTTERS
Well, I have to take medicine for it
every day. It's a little suppository
I have to ...put up my rectom.
CARTMAN
That, that's very interesting. Tell
AWESOM-O more secrets.
BUTTERS
Hm, okay. Let's see Oh, my parents
don't know, but sometimes I get picked
on by this one kid at school; his name
is Eric Cartman, and he always tries
to play jokes on me and stuff.
CARTMAN
Oh, really?
BUTTERS
Yeah. One time he made me think a meteor
had hit the earth, and convinced me
to stay down in a bomb shelter for three
days.
CARTMAN
Heh. Wow, that sucks.
BUTTERS
Yeah. And then this other time, he pretended
to be me on the phone to my dad and
called him a pussy, so my dad came home
and beat me.
CARTMAN
Wow. Sounds like this Cartman kid is
pretty smart.
BUTTERS
No, he's not smart! He's just an asshole.
And he's never gonna play on me ever
again!
CARTMAN
Really? You think so? Well, guess what,
Butters. I have a surprise for you.
BUTTERS
Yeah, and he's never gonna get me again!
'Cause what Cartman doesn't know is
that I know one of his secrets!
CARTMAN
What?
BUTTERS
When Cartman is playing all alone in
his backyard, he likes to dress up like
Britney Spears and pretend he's her!
Hi sings and dances around with a life-sized
cutout of Justin Timberlake.
CARTMAN
You saw that?
BUTTERS
Yeah! And I videotaped him doing it!
CARTMAN
Nuh uh.
BUTTERS
I've got the whole thing on tape! Even
him making out with the Justin Timberlake
cutout!
CARTMAN
No way.
BUTTERS
Yeah! And if Cartman ever messes with
me again, I'm gonna show that video
to everybody! Then I'll lhave my revenge,
boy howdy!
CARTMAN
...Um, where is this videotape, Butters?
BUTTERS
Huh? Oh, I dunno. It's around here somewhere.
Hey! So what do you wanna do now, AWESOM-O?
CARTMAN
Uh, Butters, maybe you should give AWESOM-O
the videotape?
BUTTERS
How come?
CARTMAN
Well, because... AWESOM-O can, like,
back it up for you, and make copies
and stuff. I am AWESOM-O.
BUTTERS
Oh, that's all right, AWESOM-O. Come
on! I have a lot of things to teach
you.
CARTMAN
Oh, son of a bitch!