When somebody is talking about the weather and says, “It’s windy,” I always think but almost never say out loud, “Everyone knows it’s Windy.” 
Figures, no harpsichord player on stage.
I can’t see or hear 'chicken parmesan" without out internally also hearing football legend Peyton Manning singing “Chicken parm, you taste so good” to the tune of Northwestern Mutual’s super catchy jingle. I’m not the only one, here’s a ten hour loop!
I go to Renaissance Faires. On entering the gates I must quote Firesign Theatre “Forward, into the past!”
No one has yet recognized this, and everyone who hears me believes that I am witty.
Did you say it in Catherwood’s voice? “Forrrward, into the passsssst…”
“Gee, I hope he gets back before all his dry ice melts.”
(if I were within earshot, I’d’ve said that line to you in a falsetto, like… Betty Jo Bialoski! You know, Nancy).
(from Firesign’s Nick Danger. Best old radio homage ever…)
When somebody mentions big feet, I always quote the line from Pee-wee’s Playhouse about Cowboy Curtis: “You know what they say. Big feet… Big shoes.” (The pause kills.)
Like DrFidelius’ Firesign Theatre line, most people don’t know it, so I get credit.
PS: My brother went to college
When something gets knocked over, it’s compulsory.
Whenever the family and I are rready to leave someplace, someone has to ask, ‘Shall we?’ and the only proper answer to that is - ‘Let’s.’
I go “Good bye!” a half-dozen times in my best Laurel-and-Hardy voices, accompanied by “Oh, that’s a good idea!”
When served something awful (after Ralphie on The Simpsons):
“Ohhhhh, it tastes like burning!”
Or (after Steve Allen):
“Hm! Not bad!” [Pause] “Not good…”
My favorite Ralphie-ism, the perfect non-sequitur:
“My doctors says I wouldn’t have nosebleeds so often if I didn’t stick my fingers up there!”
Me too, but now I picture Queen Elizabeth.
“How many (of something)?”
- “Too many to count, mutha 'uckers”.
At any mention of something being flipped:
- “I’m the motherflippin’”
I’ve never worked up the nerve but I always thought this would be funny to say as the doors open on an elevator you expect to be occupied.
To phone or companion: “So anyways, my doctor says…”
My response to any bullshit claim (in the voice of Beverly Hofsteder):
“I see.”
My response when anybody on TV addresses the audience with, e.g., “Hi! I’m Andrew Wommack!”:
“Hiya, Andy!”
My response when a TV commercial claims “… And it costs no more!”:
“No more than what?”
My answer to this question is, “More than I need, but less/fewer than I want.”
I had thought it originated when someone asked Charlton Heston how many guns he owned. However, I just went searching but couldn’t find an attribution to anybody.
Whenever it works: “That’s Capricorn, is it?”
A couple of things I say all the time
Any golfing outing is generally peppered with Caddyshack quotes. If someone knocks a ball into a sand trap, it’s guaranteed that someone will say, ‘Nice shot! Right on the beach!’ Or if someone is teeing up, you’ll hear “He’s a Cinderella Boy…”
You were at a church service in the rural South. Think about it…
Not from a movie or TV show (I think - in fact, I suspect it pre-dates written language) but “that’ll buff right out” is the appropriate response to almost any mishap.
“I hate it when that happens.”