1. "Frankly my dear, I don't give a damn"
Gone With the Wind

He made it through the bloody American civil war, but Clark Gable's Rhett cannot put up with the whining demands of Scarlett O'Hara, as her questions "Where shall I go? What shall I do?" are met with this response.

2. "I'm going to make him an offer he can't refuse."
The Godfather

Nobody turns down the mafia. If the Godfather asks you to cast somebody in a movie you do it, or you end up with your prize winning horse's head in your bed.

3. "Go ahead, make my day"
Sudden Impact

Clint Eastwood uttered the immortal battle lines. Eastwood's Dirty Harry character wanted to convey that he meant serious business, this is all he had to say.

4. "You talking to me?"
Taxi Driver

De Niro famously improvised the line in the mirror scene as Travis Bickle.

5. "I am big! It's the pictures that got small".
Sunset Boulevard

Gloria Swanson made the comeback her character Norma Desmond only dreamed of with this film, and this line. The film tracks the transition from the silent era to "talkies" and the pile of old stars that were left behind in the wake.

6. "I've seen better tennis playing in a tampon commercial."
Bridesmaids

Helen's (Rose Byrne) stepson utters this line, one of so many great comebacks in Bridesmaids, the new comedy classic.

7. "Why should I listen to you, anyway? You're a virgin who can't drive."
Clueless

Tai (Brittany Murphy) sums up what shallow teenagers think the important things in life are.

8. "You're gonna need a bigger boat."
Jaws

Roy Schneider's Brody addresses the giant shark attacking their litte boat with this one line. It has entered the lexicon of the English language when talking about a task with invincible odds.

9. "How can you trust a man who wears both a belt and suspenders? The man can’t even trust his own pants."
Once Upon a Time in the West

Sergio Leone's film is a spaghetti western with some oomph, and highlights that westerns aren't wooden like some people critique them as.

11. Female secretary: "I just want to know. How do you write women so well?"
Melvin (Jack Nicholson): "I start with a man. Then I take away reason and accountability."
As Good as it Gets

You don't have to agree with the message to recognise, this is a funny comeback. Nicholson excels as the snappy OCD writer with many a retaliatory comeback up his sleeve.

12. Ted Striker: "Surely you can't be serious."
Rumack:" I am serious... and don't call me Shirley."
Airplane.                                                                                                                                                                                                                                                                                                  

Airplane is what you watch for its absurdly silly and yet extremely quick lines. This is just one of many, but probably the most famous.

13. Ultrasound Technician: "I'm an ultrasound technician, ma'am."
Bren: "Well, I'm a nail technician and I think we both ought to just stick to what we know."
Juno

This is a lesson in minding your own business and keeping your moral judgements to yourself. Juno's stepmother gives the ultrasound technician a warning or two when she emphatically states how awful teenage mothers are. It's pretty hard to get in a clip but here's another equally good moment from Juno herself:

14. "You can go shave your back now."
Mean Girls

Hiss....Regina George explains the guidelines for some poor unwitting students; no, they cannot sit at her lunch table, they can, however, go shave their backs. Tina Fey has the high school/secondary school cool girls down to a T, especially with Regina George. Every school has, unfortunately, a Regina. Here she is feeling the payback:

15. "I'll have what she's having".
When Harry Met Sally

Another off-the-cuff line in the Rob Reiner film starring Billy Crystal and Meg Ryan. When Sally decides to show Harry how easy it is for a woman to fake an orgasm while they sit in ia diner over breakfast, onlookers are impressed. Fun Fact: The lady who butts in with this line is Robn Reiner's mother.

Extra:

"I never forget a face, but in your case I'll be glad to make an exception"
"I've had a perfectly wonderful evening. But this wasn't it."
"He may look like an idiot and talk like an idiot but don't let that fool you. He really is an idiot."
 Groucho Marx Quotes.                                                                                                                                                                                                                                                                                 

There is no better fella if you are looking for a one-liner, full stop.