Dewey: I'm here to snitch. Reese and Malcolm are in the garage. They won't let me in, but they're building something. If you want help in the penalty phase, let me know.
Hal: Dewey, I am not going to go in there and have a big fight with the boys because you've got nothing to do. We have a rule in this family about what we do when we're bored. [hands Dewey the TV remote]

Lois: Reese, how many times have I told you? No ice cream in the living room. You're dripping all over the rug! [Reese throws his ice cream on the floor] Are you crazy?!
Reese: No, just extremely disrespectful. I mean, what are you going to do with a kid like me? Ground me?
Lois: You bet I am. One week in your room. No TV, no video games, no contact with the outside world. After you take Alison to the dance.
Reese: What?!
Lois: Reese, you made a promise to that girl and you are going to keep it.
Reese: But how did you-?
Lois: Look, Reese, some people are born book-smart. Others are born crafty and street-smart. You, I'm afraid, are neither.

Malcolm: Seriously, Mom, think about it. You're dragging us to a place that we don't like, to buy clothes we don't care about, for money you don't want to spend, to look nice for people who hate our guts.

[As Reese sleeps, Malcolm puts his hand in a jug of water]
Malcolm: [to camera] I picked this trick up in camp last year. This is going to be great. Wait for it. Wait for it- Oh, screw it. [pours water on Reese's crotch]
Reese: [wakes up] Oh, man.
Malcolm: What's wrong, Reese?
Reese: Nothing! Just- Just shut up and go to sleep, okay?
Malcolm: [to camera] It's good to be alive.

Malcolm, Reese & Craig: [sing] We're stinky and evil, we're dumb and sarcastic While Dewey, in contrast, is super fantastic That's why Dewey is king
Craig: Why Dewey is king
Dewey: Hey, it's haircut time! Think of your favorite stooge and I'll be right back. Marshmallow, if anyone moves, eat them. [exits]
Reese: This is insane. We've got to do something.
Craig: I'm Mo.

Lois: Good morning, Malcolm. There's money on the counter for your yearbook.
Malcolm: I don't want to buy a yearbook. I don't want anything that will remind me I ever went to that stupid school.
Reese: How can you say that? Being part of a group is important. Don't you care about loyalty? I think loyalty is the most important thing there is.
Lois: Well, I'm glad at least one of my sons knows something about that.
[Reese sees the mail man walking down the drive:]
Reese: [shouts through the window] Hey! What are you doing here?! This isn't your house! You don't live here! We live here! This is our house! What do you want?! Huh?! What?! What?! What?! What?! What?! What?! What?! What?!

Francis: [on the phone] Hi, Malcolm. What's going on?
Malcolm: I just wanted to talk to you about something that's bothering me.
Francis: What's it about?
Malcolm: There's this girl, and...
Francis: Keep Mom out of it!
Malcolm: What?!
Francis: I am warning you, keep Mom out of your love life.
Malcolm: Mom has nothing to do with this.
Francis: Trust me - yes, she does. She will ruin it, I swear. Whatever Mom tells you, don't do it. And don't do the opposite, either! The way it's worked for me is... Actually, it's never worked for me.