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's Brain: Poor predictable Bart. Always takes 'rock'.
Bart's Brain: Good ol' 'rock'. Nuthin' beats that!
(at Aunt Gladys' funeral, Lisa goes up to the casket)
Lisa: Goodbye Great Aunt Gladys. I'm sorry I didn't get to know you better
Bart: (in a raspy voice from behind the casket) Don't worry about it
(Lisa runs away screaming; Bart laughs)