These are offscreen lines from Season 3.

Run, Candace, Run/Last Train to Bustville

Linda: Candace, ready to head to the library?
Sally: And that's where it goes when you flush.
Phineas: If you need us, we'll be out in the barn!
Doofenshmirtz: It's EXACTLY like Thanksgiving!

The Great Indoors/Canderemy

Doofenshmirtz: Genius! Anyway, the last episode was a cliffhanger in which Esmerelda is going to find out why Juan loves her. At least, I think that's what's going to happen... But the show got preempted by a soccer game! Oh, I hate soccer!
Doofenshmirtz: Hey, less pounding back there, okay?
Doofenshmirtz: He's getting closer...he's looking into her eyes! He's opening his mouth! He's forming his lips to start to articulate the syllables!
Phineas: Slipper chewing radio controlled by cuspids, check.
Stacy: I don't see him! What guy?
Phineas: Ta-da! Representing the molecular separator!

The Belly of the Beast/Moon Farm

Stacy: The ducks are back!
Candace: Wait a minute, why are you going to the moon?
Irving: Mission control to Moon Farm.
Jeremy: I can't wait to see what you've come up with.
Candace: Oh—uh—yeah...
Jeremy: I'll bet it's great.
Candace: Um... here's the thing.
Doofenshmirtz: Uh... Perry the Platypus? Yeah, I'm over here.

Phineas' Birthday Clip-O-Rama!

Doofenshmirtz: But I gotta stop living in the past.

Ask a Foolish Question/Misperceived Monotreme

Doofenshmirtz: A hammer? Why would someone bury a hammer? Well, onto the pile you go.
Doofenshmirtz: Not this, not this. There was a whole bunch of 'em just a couple of minutes ago. A-ha! Jackpot!
Candace: Will you stop squirming? You're a platypus. It's not like you have anywhere you need to be!
Delivery Man 1: Oh, yes. Yes, we did.
Phineas: I thought I detected a hint of western lowland gorilla.
Delivery Man 1: (sighing) No. No, that's me.
Linda: Candace? Boys? Come help me with the groceries.

Candace Disconnected/Magic Carpet Ride

Phineas: Wow, we're chatty today, aren't we?
Phineas: Okay. And go.
Contractor: Thanks, kid. Oh, forgot my pen.
Phineas: Here you go.
Contractor: Thanks kid. It had a cap.
Phineas: Oh, sorry.
Contractor: Take it easy, kid.
Linda: Lawrence, can you look at these tile samples with me? I want to re-do the living room.
Doofenshmirtz: Either way, it's nice to get out of the lab for a change and, you know, try to destroy art in the fresh air.

Bad Hair Day/Meatloaf Surprise

Carl: It was horrible down there!
Doofenshmirtz: Ooh, and some honey! See, Perry the Platypus, most people like peanut butter and jelly sandwiches but I really prefer peanut butter and honey.
Auctioneer: $70. Do I hear 75? $70 going once. 70 going twice. Oh, wait, we got 75 from the weird guy in the back.
Doofenshmirtz: Ha ha ha! The meatloaf is complete.

Tri-Stone Area/Doof Dynasty

Isabelock: Mei Phinabunk!
Can-tok: Phinabunk and Gerb!
Redundant Scribe of Redundantness: Howdy and salutations!

Phineas and Ferb Interrupted

Phineas: Oh, but we do already have one paint color for today, a second might be a little, self indulging.
Buford: The sun is on the meridian and the wind is blowing out of the southeast.

Mommy Can You Hear Me?/Road Trip

Phineas: Don't bother!
Delivery Man: Delivery.
Stacy: Mrs. Flynn-Fletcher!
Doofenshmirtz: A Gunter Flagendorf?
Doofenshmirtz: Nooooo!
Phineas: There's Perry!
Man 2: Miss, I'd like the breakfast special.

Skiddley Whiffers/Tour de Ferb

Candace Yeah, yeah, let's get this party started!
Doofenshmirtz: I won't even trap you. You can just start beating me up right away.
Baljeet: I am from India!

My Fair Goalie

Isabella: Hi guys.
Lawrence: I'm awesome, you're not, I'm awesome, you're not, I'm awesome, you're not, I'm awesome, you're not.

Perry The Actorpus/Bullseye!

Phineas: Well, Ferb came up with an idea for an exploding billboard.
Manager: Brilliant!
Mechanical mother: You were always my favorite.
Phineas: This is the one, bro. I can feel it.

That's the Spirit/The Curse of Candace

Doofenshmirtz: Moooo!
Michael: His vampire strength won't save him this time.

Escape from Phineas Tower/The Remains of the Platypus

Woman: I do love proper etiquette!
Phineas: But Saul and his crew were unemployed.

Ferb Latin/Lotsa Latkes

Norm: Out I go!
Candace: Summer is boring!
Old man #1: Hey! Where's my nosh?

What A Croc!

Phineas: Hey, Irving!
Candace: I've got evidence!

Mom's in the House/Minor Monogram

Candace: KEEP IT UP!
Linda: Do you guys already have snacks?


Linderella: Don't forget to goad the geese on your way out!
Phineas: Sure thing, mom. Get in there, Gertrude!

Monster from the Id/Gi-Ants

Doofenshmirtz: Ironic, I built my Underwear-inator while actually in my underwear.
Vivian: Hold still, Linda!

Agent Doof/Phineas and Ferb and the Temple of Juatchadoon

Candace: No, put the power drill down!
Ohio: We've found it!

Delivery of Destiny/Let's Bounce

Doofenshmirtz: I've been told so. Do you have a pen?
Paul: Yes, I do.
Doofenshmirtz: Oh, I remember this baby. Y'know, if I had a clip like that on my pen, I'd never lose it.
Linda: Well, put out ten, because I was talking to Jeremy's mom earlier, and we thought it would be fun to get us all together for brunch this morning.
Candace: I can't breathe. Where do we keep the paper bags?

Quietest Day Ever/Bully Bromance Breakup

Doofenshmirtz: Hold on, Perry the Platypus, I'm just getting the mail. Oh, goody! It's my order from the Power Tool and Sleleton Key Warehouse.
Buford: Give Dr. Toothenhurtz here his lab coats, Bright Eyes!

The Doonkelberry Imperative/Buford Confidential

Vanessa: Disappearing objects? You mean, like socks?
Baljeet: He has not been fed.
Brigitte: This way I see a score.

Sleepwalk Surprise/Sci-Fi Pie Fly

Phineas: Hey Ferb, I know what we're gonna do today! Let's build jetpacks and play volleyball!
Doofenshmirtz: Ugh, I feel like I've been up all night, which, I, I guess I have, building nice inators, apparently.
Gordon Gutsofanemu: What is the meaning of these crop circles? Why can't I time my barbecue right? Either I'm waiting an hour when they're supposed to heat up, or they're already past their peak when I bring out the steaks.

Meapless in Seattle

Doofenshmirtz: I think I misjudged his devotion!

The Mom Attractor/Cranius Maximus

Candace: This could be the most important decision of your entire summer.
Baljeet: And after the initial impact the particles will bounce up into lunar orbit! Blue skies on the moon!

Sipping with the Enemy

Doofenshmirtz: I mean, technically I haven't had any coffee here, but I've bought coffee here and I thought that would qualify.

Doofapus/Norm Unleashed

Doofenshmirtz: Well, hello, Perry the Platypus! Over here.
Phineas: Sure! We'll just need to whip up some more nano-bots!

When Worlds Collide/Road to Danville

Doofenshmirtz: Oh, that. The beam that I shot through my roof?
Doofenshmirtz: (during song) Ow! Ow! Oh!...No really, it's huge, you should see it.
Doofenshmirtz: No, no, you're right, by myself.

Where's Perry?/Where's Perry? (Part Two)

Carl: Weak. Weak. Weak. Weak. Weak. Weak. Weak. Weak. Weak. Weak.
Doofenshmirtz: If you can manage it, I need a ball-joint compressor.
Buford: Okay, But I don't know what you're gonna do with half of a vine.

Blackout!/What'd I Miss?

Candace: Oh who leaves a chair right next to a table?
Doofenshmirtz: Aaaahhh! Let me off of this thing! Ow! Ow! Aaahhh! Ow, ow! Not that hard! Not that hard!

This Is Your Backstory

Doofenshmirtz: Ow! Why!? Why!?
Norm: Thank you, don't break the rhythm, sir.
Charlene: Nice tux, Norm.
Doofenshmirtz: Do they have blowing-up insurance? I should get some of that.