Lisa Marie Simpson, voiced by Yeardley Smith, is Homer and Marge's oldest duaghter and the middle child on The Simpsons.  Lisa is very intelligent, plays the saxophone, is a vegetarian, Buddhist, and definitely a bit of a young political activist.  She's basically the complete opposite of her brother, Bart.

Lisa Simpson Quotes

Bart: I call first bedsies!
Lisa: Bart, there's no such thing as first bedsies. You just made that up.
Bart: Well, okay. Which one do you want?
Lisa: I ... want ... that one.
Bart: Really? You want that one? Well, it's all yours, whatever you say.
Lisa: Why, what's wrong with it?
Bart: Nothing! Have a good night's sleep, Lisa.
Lisa: No, really, what?!
Bart: Nothing!
Lisa: What did you do to it?
Bart: Nothing!
Lisa: MOOOOOM!

So now Andy is a TV writer? Loser.

Lisa

The Simpsons Quotes

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

Bart

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!