Bartholomew "Bart" Simpson is voiced by Nancy Cartwright (that's right, a woman!) and is Homer and Marge's only son on The Simpsons.  Bart is an underachiever and was definitely much more of a bad boy in th ebeginning seasons of the show.

Now, Bart, although he has not aged, has certainly matured as a character.  Do the Bartman people.

Bart Simpson Quotes

Bart: From A-Apple to Z-Zebra, "Baby's First Pop-up Book" is 26 pages of alphabetic adventure!
Edna: Bart, you mean to tell me you read a book intended for preschoolers?
Bart: Well, most of it.

Wow, now I see why they call you Miss Hoover. You must have been vacuuming for an hour.

Bart

The Simpsons Quotes

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!

Horst: (Sinister) Okay, Mr. Burns, you win. But beware. We Germans aren't all smiles and sunshine.
Mr. Burns: (Sarcastic) Oooh, the Germans are mad at me. I'm so scared! Oooh, the Germans! (Hiding behind Smithers) Uh oh, the Germans are going to get me!
Horst: Stop it!
Man: Stop, sir.
Mr. Burns: Don't let the Germans come after me. Oh no, the Germans are coming after me.
Man: Please stop the "pretending you are scared" game, please.
Horst: Stop it! Stop it!
Mr. Burns: (Pause) No! They're so big and strong!
Man: Stop it.
Horst: Stop it, Mr. Burns.
Man: Please stop pretending you are scared of us, please, now.
Mr. Burns: Oh, protect me from the Germans! The Germans--
Horst: Burns, Stop it!