From the pilot, when Philip comments on the slang Will uses when he first arrives:
Vivian: We used slang when we were kids! Do you remember our first date? You took one look at me and said, "Vivian, that is a bad dress." Now, you could've just said it was a good dress. Philip: I could've if I liked it. Actually, it was a bad dress.
Carlton's basketball team and the coach's deadpan expression and remarks.
In "Banks Shot," Will notices the car keys on the table after his uncle has left. He has a conversation with his Shoulder Devil who tells him to take it and go to the pool hall; when he looks to his other shoulder for more advice, another Devil appears. "What are you, ignorant? Pick up the damn keys!" And then the second devil Dope Slaps him.
Will, Carlton, Ashley and Hilary cooking Thanksgiving Dinner in "Talking Turkey."
Will and Carlton's mad dash to ask a girl they both see from opposite sides of the mall out at the end of the first part of "Someday Your Prince Will Be In Effect."
When the kids won't stop bothering Philip about wearing a costume to the Halloween Party:
Philip: I'm going as Comfortable Man.
Hilary: Is that a comic book hero?
Philip: Sort of. He has superhuman bill-paying power so he gets to dress however he wants.
Ashley: [quickly gets it] Great costume, daddy.
Geoffrey knows the lambada? "That's the forbidden dance!"
At the end of "Striptease for Two," Phil discovers that Will and Carlton have been stripping for cash to make back the money they lost from a bad stock tip. They break down and tell him that they also pawned one of Vivian's bracelets in order to get the money for the stock in the first place...and they never bothered to get the clasp fixed. Hearing all this, Phil begins to laugh, with Will joking that instead of punishing the two of them, he ought to reward them for their honesty, because "Hey...it worked for the Beav!" At this point, the three of them are laughing hysterically together, when suddenly Phil snaps: "DO I LOOK LIKE A WHITE GUYNAMED WARD?"
Phil: Now you get that bracelet back, and for the next six weeks, I don't want to hear you breathe...OR I'M CALLING THE FEDS MYSELF! (leaves)
Will: (scared) I guess this probably ain't the best time to tell him we ran over the mailbox.
In "Did the Earth Move For You?", the scene that YouTube users refer to as "The Earthquake Song" set to the tune of "Darling Nikki" by Prince.
Will: *singing* I'm stuck in a basement, sitting on a tricycle, girl gettin' on my nerves. (pause for audience laughter) Goin' out of my mind, I thought she was fine, don't know if her body is hers.
In "Ill Will," Will, Carlton and Hilary hide under Geoffrey's bed as Phillip and Vivian barge in to look for Geoffrey's memoir of the family. Phillip sits on the bed, crushing the three.
The revelation that Hilary was conceived at a Sly Stone concert.
Will: And I hope those concert tickets weren't front row. Hilary: Ew! Is that why you always play "Hot Fun in the Summer Time" on my birthday? Carlton: And where was I conceived? Will: Probably at a white sale.
Will: (turns to Tyriq) You should have known it was fake when you saw that the warranty was only for two hours. (turns to Jazz) And you should have known that the Jackson on a twenty ain't Jermaine.
Will's blues solo from "Geoffrey Cleans Up" in response to Geoffrey not wanting to date a rich woman:
Will: My butler is black. My butler is blue. 'Cuz his honey got green... coming' out her wazoo.
In "Be My Baby Tonight," Ashley asks Will about sex. He has no idea what to tell her, so he opts to confer with Hilary and Carlton. Will believes someone with more experience should talk to Ashley, so he and Carlton immediately look at Hilary.
Hilary: Well, pardon me for being attractive.
Listen closely to the studio audience's reaction to that line. You can actually hear James Avery laughing with the crowd.
In the episode "Mama's Baby, Carlton's Maybe," Will is trying to comfort Carlton after his girlfriend leaves him at the wedding chapel and Carlton admits he is a virgin. When he first says it, a man walking by with his fiance who he just found out is pregnant says, "Well, at least somebody still is!"
Carlton: You mean you're a virgin too? Will: Keep your voice down man, I AIN'T NO VIRGIN!(woman in front of him gets up and leaves) Hey, look man, when it comes to me and the honeys I just say (priest walks up to him) de...no way! Ooh, ugh yucky!
Will's phone conversation with his mother about the incident.
"Ma, you'll never guess who's a daddy. No ma, not me, stop cryin'. No, ma, it's Carlton. (Beat) Ma, stop laughin'.
A few seconds later, the family enters and Will pretends to be ordering a pizza.
"Uh, yeah, 20 minutes? Great. Ok. Uh, I love you (Hangs up, turns to the others) That makes them bring the pizza faster."
Will and Uncle Phil are trapped in an elevator at the hospital where Vivian is going into labor. Both are in desperate need of a phone to call Geoffrey at home, and it just so happens that they're trapped alongside a businessman who happens to have one...and who won't give it up. Will then decides to exercise his "straight-out-the-hood" negotiation skills on him, and we Gilligan Cut to...
Will: (dancing and singing) Please, can we use your phoooone? (stops) Yo, if you don't let us use your phone, I'ma start singing Paula Abdul's Greatest Hits!
And after the guy says something obnoxious, a shocked Will responds with: "Stop!Ghetto time!"
In "Mommy Nearest," Will is shocked when his mom tells him that she's going to take him back with her to Philadelphia, as he wants to stay in Bel-Air and go to college. Will's fear is illustrated by his mom repeating the line faster and faster until it cuts to Stock Footage of an explosion.
And later, Will has an Imagine Spot of him still living with his mom as an old man.
And this awkward moment:
Mrs. Smith: You want to go back to Philadephia, don't you baby?
Will: Whoosh. (tosses his hat) Look what the wind did to my hat.
"Robbing the Banks" has the family hiring an ex-con as a handyman. They're naturally suspicious but Will constantly proclaims the man's innocence. Gilligan Cut to the entire living room empty of furniture and Will freaking out.
The Courtroom Antics that occur in "Will Goes a Courtin'", especially Phil and Will's sides of the story.
In Phil's version, Will and Carlton are thuggish, and everyone is wearing revealing swimsuits, including the 15-year-old neighbor girl who wandered over. Phil himself is just a meek, quiet man who accidentally steps on Carlton's inflatable duckie inner tube.
Not to mention Carlton's line: "HEY POPS! YOU POPPED MAH DUCK!"
In Will and Carlton's version, the pool party is a classy, innocent affair where everyone is in old-style bathing suits and they dance in a circle holding hands. As Phil enters, a glass of water shakes a la Jurassic Park and he rips the head off of Carlton's duckie inner tube. He also yells at the 15-year-old neighbor girl who "wandered over, crying" as Will says. ("Hit the bricks, you little tramp!")
Speaking of Carlton's duckie tube, he calls it "Howard". And he runs off crying like a little girl when Phil pops it just because he tried to stand up to his dad. This is in Will's side of the story too, only more exaggerated.
An episode ends with Will in a philosophy class and the teacher posing the classic question of "If a tree falls in the forest and no one's around to hear it,does it make a sound?". Will responds confidently at first, then veers completely off course, asking how big the tree is, if it fell on a gopher and if the sound the gopher would make would count, and what if it fell on his Uncle Phil and that hurt the tree.
Season 4 ended with a Wham Line where Will decided to remain in Philadelphia with his mother. Season 5 opens with an NBC executive showing up and pointing out that his contract says "Fresh Prince of Bel-Air", then tossing him in a van and taking him back to California.
The best thing is the clip from the opening theme that plays immediately before the opening: "Yo, homes! To Bel-Air!"
"Will's Misery" revolves around a prank in which Will is kidnapped, restrained and tortured by his date to teach him to respect women. When Will discovers Carlton was behind it all, he gets payback. Will tells Carlton about the abduction... except in this version, Will got loose and killed the girl with a rock. And her body's still up there. Carlton, in a fit of despair, runs out the back door, around the house into the living room, back into the kitchen dragging himself across the floor to the back door again, into and through the backwoods cabin, intothe audience, out the elevator into the University Cafeteria, and finally off-stage into Will's arms. Freeze scene, audio continues to play clapping, cut to black.
In "Cold Feet, Hot Body", Carlton responding to complaints about customers not getting bacon in their BLT's by claiming that the "b" doesn't have to stand for "bacon".
Will:Bread, lettuce, and tomato?!
"To Thine Own Self Be Blue... And Gold" has one of the funniest subplots in TV history where Carlton and Hilary both sign up for an online dating service and unknowingly get set up with each other. Let's just say they milked it out for every bit of humor they could get away with.
From "Not With My Cousin, You Don't":
Carlton is done upgrading the Banks' household intercom system, eagerly wanting to show off one of its features.
Carlton: Check out the exciting new roam feature. Let's listen to my room. [Carlton presses a button, then smiles giddily.] Well, all's quiet in there! Will:[imitating Carlton's giddy look] Ooh, there's a surprise. Carlton: Subject: Geoffrey's room. Geoffrey: I wonder how I'd look if I shaved my entire body.
Once Derrick arrives, both Will and Carlton have this discussion:
Will: You're rounding third base and you're headed for home. You're excited because you think you're about to score easy, but here's the problem: You're in the visitor's ballpark and if you do score, angry fans might not be able to be held responsible for their actions. Carlton: And... it's bat night. Derrick: Are you two in trouble with a bookie or somethin'? Carlton: Let's stop beating around the bush! You're playing chess. Your rook has been blindsided by the queen's gambit. Now you can play honorably — leave your bishop at home to protect your queen's virtue — or you can take the sleazy road and castle your king... and go right for the mate. Will: And... it's bat night!
"Burning Down The House": Carlton tries to hitchhike his way home, which leads to this:
Hippie: So what I'm saying is there shouldn't be a "rich" or a "poor." We should all just share the wealth, man! Carlton: Oh, I beg to differ. (the hippies literally throw Carlton out of their microbus)
All the times that Uncle Phil throws Jazz out of the house are guaranteed to bring some laughs. Highlights include the one time he threw Jazz inside the house when they were already outside, and the time when Jazz got his revenge by throwing Uncle Phil out of the house in Will's dream.
LITERALLY every single one of Will's pick up lines:
Will: Baby, you look so good I wish I could plant you and grow a whole field of y'all.
Will: Girl, you look so good I'd marry your brother just to get it your family
Will: I could've sworn I've seen you before. Oh yeah, it was in the dictionary right next to the word "KA-BLAM"!