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!
Bart: I didn't know you knew Luke Perry.
Krusty: Know him? He's my worthless half-brother.
Lisa: He's a big TV star.
Krusty: Yeah, on Fox. (Sticks out tounge)