Lisa Simpson: Gifted child activist or "Springfield's answer to a question nobody asked?" If you look at her actions throughout all 32(!) seasons of The Simpsons, you'll see the answer falls somewhere in between.
We've seen her try to inspire a generation of little girls with her "Lisa Lionheart" dolls (or "aspiration figures," excuse me) and helping to picket for workers' rights. We've also watched as she's ruined barbeques and put her brother Bart in life-threatening danger several times. What's clear is she'll never stop trying to make her town of Springfield into a better place, even if she accidentally makes it worse in the process.
10 Saved: When She Stopped Sideshow Bob From Becoming Mayor
Robert Underdunk Terwilliger, better known as Sideshow Bob, has been one of the Simpson family's most popular recurring villains throughout the series. In the fifth episode of season six, "Sideshow Bob Roberts," he plots to ruin the Simpsons' lives by becoming the new Mayor of Springfield and passing legislation that will make their lives miserable.
While the town seems to be enchanted with the newly titled Mayor Terwilliger, he secretly looks down on them and believes they need him as he will "lower taxes, brutalize criminals, and rule [them] like a king." Believing that Bob's landslide victory seems odd, Lisa launches an investigation and discovers he rigged the election, with most of his votes coming from long-dead citizens and pets. Bob is arrested and sent to a minimum-security prison for white-collar criminals where he (once again) swears revenge.
9 Made Worse: When She Helped Decimate Springfield's Sea Life
When Mr. Burns goes broke in "The Old Man and the Lisa," the twenty-eighth episode of season 8, Lisa is at first satisfied, as he was one of Springfield's biggest polluters. However, after Burns appreciates Lisa's honesty, she decides to help teach him to be a more conscientious person.
Her plan backfires tremendously after Burns gives her a tour of his new factory, revealing a massive series of nets made from recycled plastic, which he uses to fish the sea dry. He explains he had the idea after hearing Lisa talk about how fish get caught in plastic pollution dumped in the ocean.
8 Saved: When She Stopped the Release of the Funzo Doll
After Springfield Elementary goes bankrupt, it is quickly purchased by Kid First Industries, a toy manufacturer. Unknown to the town, the corporation has repurposed the school into a marketing facility using the students to act as focus groups. During the Christmas season, Kid First unveils their new toy: Funzo, a Furby-Esque doll that "makes playtime fun."
After she is gifted one early, Lisa discovers that the Funzo dolls are programmed to eliminate their competition and destroy any other toy their owner has. Her solution is to enlist Homer to pull a How The Grinch Stole Christmas type heist, and steal every Funzo in town before they can be opened Christmas morning.
7 Made Worse: When She and Mensa Took Over Springfield
In "They Saved Lisa's Brain," the twenty-second episode of season ten, Lisa is invited to join Mensa and finally finds herself among intellectual peers. Things go awry when they are temporarily put in charge of Springfield after Mayor Quimby flees town.
While they intend to turn Springfield into a utopian society, their ideas such as banning all sports and a breeding policy inspired by the Vulcans from Star Trek turn the town against them. With the timely intervention of guest star Stephen Hawking, Lisa escapes a riot and sees the error of her ways.
6 Saved: When She Put an End to Whacking Day
In "Whacking Day," the twentieth episode of season 4, Lisa tries to put a stop to the titular holiday, wherein all of Springfield rounds up snakes and whacks them to death. This leads her and Bart to dive deep into the tradition's origins, and discover it's rich history is actually a sham. The holiday was actually started just several decades earlier as an excuse to beat up the Irish.
With the help of special guest star Barry White, Lisa is able to bring all the town's snakes into the Simpson household and reveal the holiday's real history to the town. Convincing all of Springfield to embrace snakes and end Whacking Day for good may not be physically saving Springfield, but it's a definite moral victory for Lisa.
5 Made Worse: When She Inspired Homer to Flood the Town
Homer accidentally becomes a celebrated outsider-artist in "Mom and Pop Art," the nineteenth episode of season 10, after a failed attempt to build a barbeque pit is mistaken for an avant-garde sculpture. When his next art installations are criticized for their lack of creativity, he turns to Lisa for help.
She tells him he should look at the experimental works of other artists such as Christo, which gives Homer the idea for his masterpiece: flooding the town and setting free zoo animals equipped with snorkels and flippers, in an attempt to make the streets of Springfield resemble the canals of Venice.
4 Saved: When She Covered Up The Truth About Springfield's Founder
"Lisa the Iconoclast," the sixteenth episode of season seven, shows Lisa discovering another piece of Springfield's history is a sham. The town's founder Jebediah Springfield was, in fact, a pirate named Hans Sprungfeld, who attempted to murder George Washington.
While Lisa sets out to expose the truth to the town, she realizes how important the myth of Jebediah Springfield is for everyone. She decides to cover up what she knows and let the people of Springfield go on believing that their town was founded by an American hero rather than a criminal with a solid silver prosthetic tongue.
3 Made Worse: When She Destroyed Springfield's Oldest Tree
When she develops a crush on a radical environmentalist, Lisa decides to live in the oldest tree in Springfield in order to save it from being cut down. In the appropriately named "Lisa the Tree-Hugger," the fourth episode of season twelve, she soon realizes that the job is more daunting than it first appeared.
After she climbs down from the tree for a couple of hours to see her family, she sees on the news that a lightning strike has knocked down the tree. Even worse, the lightning was attracted to the tree by a metal bucket Lisa had left behind in its branches.
2 Saved: When Her Speech Got a Corrupt Senator Arrested
Lisa has her faith in democracy shaken in "Mr. Lisa Goes to Washington," the second episode of season 3, after she overhears one of her state's congressmen being bribed to ignore the destruction of Springfield Forest. To make matters worse, she's in Washington DC after entering an essay contest about what makes the U.S. great.
Her disillusionment causes her to rewrite her essay, changing it into an angry criticism of corruption in U.S. politics and naming all the people involved in the bribery she witnessed. After she makes her speech at the contest, the federal government is uncharacteristically moved and the corrupt congressman is arrested, thereby saving Springfield Forest.
1 Made Worse: Caused a Massive Riot at a Hockey Game
In "Lisa On Ice," the eighth episode of season six, Lisa joins a pee-wee hockey team after proving herself to be a gifted goalie. This sets her on a collision course with Bart, who plays for a rival team.
When their two teams play against each other, the Lisa vs. Bart face-off has been hyped up to epic levels. Instead of fighting during the game, Lisa and Bart remember how much they love one another and leave. The crowd, who had been expecting a fight, begin to riot and destroy the stadium. This one isn't actually Lisa's fault, and like many of the times that she's made Springfield worse, it's because she's trying to do the right thing. She's only eight years old after all, give her a break.