Clark Gable as Rhett Butler in “Gone With The Wind”.
Frankly, my dear, I don’t give a damn.
Another Bogie: “(if you need anything) just whistle”. To Lauren Bacall, no less…
Also
“You’re despicable”
“Rabbit Season!” “Duck Season!”
“Pronoun trouble”
“Where’s the kaboom? There was supposed to be an earth-shattering kaboom!”
“Monsters are such interesting people”
“Consequences, Schmonsequences, as long as I’m rich.”
“HO! HA HA! GUARD! TURN! PARRY! DODGE! SPIN! HA! THRUST!” WHACK
The list goes on for a long time.
“Of course, you realize this means war.”
(Or does Groucho get that one?)
This is the only one I recognise from the list of Al Pacino.
No, that was Lauren Bacall to Bogart, from To Have and Have Not.
“You don’t have to say anything, and you don’t have to do anything. Not a thing. Oh, maybe just whistle. You know how to whistle, don’t you, Steve? You just put your lips together… and blow.”
It’s from Five Easy Pieces: http://www.youtube.com/watch?v=6wtfNE4z6a8
Not even “Attica! Attica! Attica!”?
I never saw the movie, either. shrug The 70’s had a lot of anti-authority movies. Some light hearted, some not.
Ok. What’s the rules about starting threads? Bricker posted once (the OP), and that’s it. 
Guess which iconic line was referenced in Teenage Mutant Ninja Turtles II: The Secret of the Ooze? The Casablanca one. 
Spoiler: The Ooze’s secret is its childhood sled.
This has gone from quoting iconic lines to just quoting “lines I really like and, therefore, must be iconic.” I don’t mean to single you out, Quartz but none of those lines delivered by the great Alan Rickman are anywhere near approaching iconic.
We’re also dealing with some generational issues here. Among my generation (whatever’s between Gen X and Millennials), “Get to ze choppa!” is most definitely iconic (and often ironic!). I can quote it without explaining its origin, in a context completely divorced from the one in which it was said in the film, no one would raise an eyebrow, and yet EVERYONE would know I was quoting something. I can do the same thing with those lines from Casablanca. Both are iconic, but the Casablanca lines are MORE iconic, if that makes sense.