Doctor: Mrs. Simpson, I'm sorry, but your husband suffers from a persecution complex, extreme paranoia, and... bladder hostility.
Marge: Doctor, if you just talk to him for five minutes without mentioning our son Bart, you'd see how sane he is.
Doctor: You mean there really is a Bart? Good lord!
Leon Kompowsky: [in Michael Jackson's voice] Hi, I'm Michael Jackson from The Jacksons.
Homer: I'm Homer Simpson, from The Simpsons.
Bart: [singing] Lisa, her teeth are big and green. Lisa, she smells like gasoline. Lisa, ta-ra-ra Lisa. She is my sista, her birthday I mista.
Leon Kompowsky: We call this one the Chief. He's been here since 1968. Never says a word. Never moves a muscle.
Homer Simpson: [waves] Hey, Chief.
Chief: [waves back] Hello.
[all the doctors gather around muttering and writing notes]
Chief: Well, it's about time somebody reached out to me!
[Homer is calling home from a mental institution]
Bart: Joe's Taxidermy. You snuff 'em, we stuff 'em.
Homer: Boy, when I get home, I'm gonna wrap my hands around your neck and...
[noticing the orderlies glaring at him, he relents]
Homer: ...smother you with kisses.
Bart: Homer, whatever they've got you on, cut the dose.
[answering the phone]
Bart: Joe's Crematorium. You kill 'em, we grill 'em.
Montgomery Burns: Why is that man in pink?
Waylon Smithers: Oh, ah, that's Homer Simpson, sir; he's one of your boobs from Section 7-G.
Montgomery Burns: Simpson, aye? Well, judging by his outlandish attire, he's some sort of free-thinking anarchist.
Waylon Smithers: I'll call security, sir.
Montgomery Burns: Excellent. Yes, these colored monitors have already paid for themselves.
Homer: [yells after being shown an inkblot that looks like Bart] The boy!
Leon Kompowsky: You know Bart, when I was growing up I didn't have much money. So you know what I did every time my sisters' birthdays rolled around?
Bart: Stiffed them?
Leon Kompowsky: No Bart, I wrote them a song to show them I cared.
Bart: I can't write a song! I'm only ten.
Leon Kompowsky: *Only* ten?, When I was your age, I had six Gold Records.
Bart: Hey, Looney Tunes...
[pulls out the "Thriller" album]
Bart: *this* is what Michael Jackson looks like! You just look like a big, fat mental patient!
Leon Kompowsky: You'd be amazed how often I hear that, Bart.
Homer Simpson: [trying to scrub off hand stamp that reads "insane"] Come off! I'm sane now!
Homer Simpson: [after Leon moonwalks] How do you do that thing with your feet?
Leon Kompowsky: You mean the moonwalk?
Homer Simpson: No! That thing with your feet!
Doctor: After analyzing your husband, we have determined that he's not a danger to anyone.
Homer Simpson: That's the nicest thing anyone's ever said to me. Can I have it in writing?
Bart: [Lisa wakes up Bart] Lisa, it's 6 a.m., what's wrong? Dad died?
Lisa Simpson: No, no, no, he's fine.
Bart: Whaddya know, I'm relieved!
Bart: [Homer gives a mental health questionnaire he's supposed to complete to Bart] Dad, maybe you should fill out this form.
Homer: Son, it's no different than the time I let you vote for me. Remember that absentee ballot?
Bart: Oh, yeah!
[Homer quickly gets absorbed in a "funniest home videos" show on the TV]
Bart: Hey, Dad, do you hear voices...?
Homer: [annoyed] Yes, I'm hearing one now, while I'm trying to watch TV!
Bart: [checks] "Yes." Are you quick to anger...?
Homer: [raises a fist] Bart! Shut up or I'll shut you up!
Bart: [checks] "Yes." Do you wet your pants...? Well, even the best of us has an occasional accident.
[he proceeds to check "yes" for all remaining questions]
Dave: Okay so I was working an insurance company right
Dave: youngest VP in the history of the firm, okay the job was my life
Dave: then one Monday morning
Dave: I got up I couldn't leave the house, I just couldn't
Homer: Was the door locked?
Dave: No, I just couldn't face what was out there
Homer: Was it raining?
Nurse: No Homer, Dave suffers from agoraphobia: a fear of open areas and crowds, please Dave go on
Dave: Thank you, anyway that day I, I just couldn't make that long drive to work
Homer: Were you out of gas?
[the nurse glares angrily at Homer]
Homer: [turns toward Dave] Pfft baby!
Homer: Lisa, you like homework. Would you fill out this form for me?
Lisa Simpson: Well, all right - if you listen to the poem I just wrote.
Homer: D'oh...! Uh, okay.
Lisa Simpson: "Meditations on Turning Eight," by Lisa Simpson. "I had a cat named Snowball, she died, she died! Mom said she was sleeping, she lied, she lied! Why, oh why is my cat dead? Couldn't that Chrysler hit me instead? I had a hamster named Snuffy, he died!"
[that's all she wrote, literally]
Homer: No deal.