Nephews: We missed ya, Unca Scrooge! Scrooge:Missed me? What'd you throw at me?
The infamous "A SEA MONSTER ATE MY ICE CREAM!!!!!!", which consists of Scrooge flipping out over hearing such news (since it was actually half his fortune), repeatedly screaming the above phrase and bouncing on the breakfast table on his head.
Ms. Beakly: That must've been some ice cream.
His nephews were forced to strap him in a makeshift straightjacket, which calmed him down, and he then proceeded to hop away determined to get his fortune back.
Gladstone freaking out after Magica de Spell curses him with bad luck in "Dime Enough for Luck". "I don't believe it! I've lost my luck! No food... no money... gasp! I'll have to get a job like normal people!!"
From "Sweet Duck of Youth": Looking into the fountain of youth shows the person as they looked when they were younger. For the triplets, the reflection is just three giant eggs staring back at them.
Dewey: We havenít even hatched yet!
Not to mention Launchpad's reaction to seeing himself as he younger self from an earlier episode!
Launchpad: Oh no! Now I'll have to start all over!
From "Super Ducktales":
Fenton's attempts to get the bag of dimes from the Beagles. All of them.
Ma Beagle:[chasing Huey, Dewey & Louie] Come back with that cash! Burger:[follows] Come back with those desserts!
"It's thieves like them who are making the world a rotten place to live for thieves like us!"
"If ya don't like how I drive, stay out of the hallway!"
"But I'm too young to die! And too nice! And much, much too nervous!"
Later in that same episode:
Scrooge: What's going on? High noon isn't for another hour! General Chiquita: I thought I would save you needless anguish by moving up the execution. Fenton: Bu-but I was just starting to enjoy my anguish!
"This'll make a nice cover photo for Duckweek - Scrooge and his nephews... [Burger turns back to normal] ...playing Beagle Boys and Indians. ...BEAGLE BOYS??!"
Earlier from the episode.
Scrooge: My nephews and I just love to play cowboys and Indians Woo-woo-woo-woo! Woo-woo-woo-woo!!
From "Nothing to Fear":
Scrooge: Duckworth? Why are you standing in the closet?
Duckworth:[clears throat, whispers] Because there's no limo monster in here, sir.
Scrooge: Well, I guess he has a point.
At the climax:
Huey: We're not afraid of you, Ms. Quackenbush! We did our homework!
Nightmare Quackenbush: Oh. Sorry! [Vanishes]
Scrooge is performing a ship christening:
Scrooge: Is this cheap champagne?
Duckworth: The cheapest, sir.
The best part is that he pauses in midswing to ask.
"The Ducky Horror Picture Show"
Scrooge: Huey, Dewey... [the Blob slithers down the stairs] Yucky! [the Blob slithers over him, covering Scrooge in slime] Scrooge: Eck! I've been slimed by the Blob! Duckworth: There's a first time for everything, sir.
Quackymodo: Hey McDuck, you want to Blob for apples? HA HA HA HA HA! [pointing at a bucket of apples floating in green slime] [The slime is the Blob who's eating the apples] Scrooge: Yuck!
The ending to "Take Me Out Of The Ballgame" - Doofus hits the baseball so hard that it travels halfway across the world to Europe and beans Launchpad in the head, knocking him out and causing a crash landing.
In "Duck to the Future":
Scrooge: Gyro, it's me! Scrooge McDuck! Old!Gyro:(shakes Scrooge's hand) Please to meet you. What can I do for you? Scrooge: You got to help me, Gyro. What happened to your Time Tub? Old!Gyro: I give up. What? Scrooge: Think! Old!Gyro: Oh yeah, it's over there. I turned it into a bird bath. Scrooge: You got to fix it! I gotta get back to the past! Old!Gyro: Who are you? Scrooge:SCROOGE MCDUCK!!! Old!Gyro: Please to meet you. What can I do for you? Scrooge: *Face Palm* Great scotts!
Scrooge: Will the Time Tub work? Old!Gyro: Will what work? Scrooge: This bird bath! Old!Gyro: This isn't a bird bath, it's a Time Tub. Scrooge: I don't care what it is! Just get me back to the past!
In "The Duck in the Iron Mask," Dewey gets upset when the announcer at their baseball game calls him "Huey."
Dewey: I'm sick of people getting us mixed up all the time!
Scrooge: Launchpad, why start now and ruin a perfect record?
Scrooge has plenty of moments with Launchpad and Fenton Crackshell, really. Mostly in the form of being a Deadpan Snarker who sometimes tosses Stealth Insults.
This excerpt from the intro to the Transylvania level.
Scrooge: Dinnae worry. Iíll be back with the coin before you can say "E Pluribus Unum." note "E pluribus unum" is a phrase found on the back of the American dollar bill (among other things). It is Latin for "Out of many, one".
Hewey: Ee purple bus who-um?
Louie: Yeah. Iím not sure thatís as fast as you think it is.
The face Scrooge makes in the Himalayas, when he gets stuck in the snow.
It gets better, he makes that face on the picture in the music gallery for the modern!remix of the song.
During the mini-boss battle with Flintheart Glomgold in the Himalayas level, Webby sometimes says to Scrooge "Pretend he's a door-to-door salesman!"
In the same scene, Launchpad might sometimes say "Usually, for a ride like this, you'd have to buy a ticket."
One of Magica's taunts during her boss battle, when she uses her lightning bolt spell.
Magica: Fried Scrooge, order up!
Her monologue after her defeat is pretty good, too:
Magica: Blast these inferior mirror and beam spells! Is last time I shop for spell ingredients at discount store!
The post-level conversations that Scrooge has with his nephews have some entertaining moments. For instance, there's the one that takes place after Africa, where Scrooge tells the boys that it was silly to think that a ghost was the source of the mysterious voices in the diamond mines—that there's always a rational explanation for this sort of thing. Dewey immediately lampshades the real reason for the voices: