Funny, but at the same time pretty scary: Shirley drinks some cocoa on a train and starts choking and trying to communicate that it's poisoned by doing charades.
Shirley: There's better guys. Handsome, rich guys with class!
Squiggy:(he and Lenny wear bathrobes, Squiggy has his leather jacket on) Hello!
When Shirley prays:
Shirley: I'm a good girl! I'm not a bad girl, I'm not...
Squiggy:(dressed as a red devil with a trident, Lenny's dressed as a masked cowboy) Shirl!
Shirley:GOOD GOD! IT'S THE DEVIL AND HOOT GIBSON! AAAHHH!!!
Anytime Laverne and Shirley have a singing duet, particularly their goofy performance of "Da Doo Ron Ron" in pink dresses in the episode "Citizen Crane" (getting hampered by their own dresses and cables, the two lifting their dresses French Cancan-style, Shirley almost falling backwards when she's lifted by the backup dancers etc).
When Shirley finds out that Laverne is afraid to drive in "Drive, She Said", she teases her by shouting out, "Laverne DeFazio is afraid to drive!", which results in both of them shouting out each other's secrets and ends with Laverne shouting, "Shirley Feeney stuffs socks in her bra!".
In "Bowling for Razzberries", Laverne flirts with the doctor who is trying to examine her.
When Lenny and Squiggy hear that Laverne might be pregnant in "Look Before You Leap", they say, "Whoa!".
Laverne: "What are you whoa-ing about?"
Squiggy: "Shirley told us you were gonna have puppies."
During an argument, Laverne says "Don't yell at me while I'm yellin' at you."
In "Good Time Girls", Laverne and Shirley walk into a bar disguised as men to go to the men's toilets (Laverne wears a baseball jacket and a leather cap to cover the entirety of her hair and Shirley looks like an odd Elvis/Squiggy/Greaser Delinquent mix). They quite poorly disguise their voices and look awkwardly skinny in the middle of several tall and jacked male patrons in there.
In an interview with the Television Academy, while the two leads are discussing the series' iconic opening hopscotch chant* "One, two, three, four, five, six, seven, eight! Schlemiel! Schlimazel! Hasenpfeffer Incorporated!, Penny Marshall mentioned she had no idea what "hasenpfeffer" actually means. Her reaction when Cindy Williams told her it means "rabbit"* which is only half right; it's actually a stew made from rabbit or hare meat is nothing short of priceless.
