When I think about which are some of the most powerful movie lines, the climactic speeches/monologues in two movies rule:
-- A Few Good Men
-- Scent of a Woman
And irrespective of how many times I listen to them, they refuse to be superceded by today's pop clutter movies. An elaboration:
# With the great reluctance that he is put on the trial stand, in his hard-hitting trial speech, Col Jessep (Jack Nicholson) in Few Good Men, for a while, makes it impossible to distinguish between good and bad. The proposition in his speech ("We use words like honor, code, loyalty. We use these words as the backbone of a life spent defending something. You use them as a punchline." ) make the call-of-the-nation/duty sound so supreme that you almost forget the protagonist (Tom Cruise as Lt Kaffee) and are willing to forgive the supposed-to-be-villain for all the misdeeds he committed.
The epilogue to this fantabulous monologue is actually a dialogue which is the quintessential "out-with-it" build-up to a face-off between Nicholson and Cruise. Undoubtedly one of the best, and most impacting: "Col. Jessep: You want answers? Kaffee: I think I'm entitled. Col. Jessep: You want answers? Kaffee: I want the truth. Col. Jessep: You can't handle the truth."
# On Al Pacino in Scent of a Woman, well, one can not appreciate enough the turnaround in a situation where once-despondent Lieutenant Frank (Pacino) turns into a ferocious saviour of merit and free speech and an antagonist to the system that rewards sychophancy and connectedness. The way he advocates for the young protagonist, Mr Simms, your heart goes out to both of them and you are instantly overwhelmed with the booming voice and with the courage human spirit shows once pushed to the wall ("Who the hell do you think you're talkin' to? I've been around, you know? There was a time I could see. And I have seen. Boys like these, younger than these, their arms torn out, their legs ripped off. But there isn't nothin' like the sight of an amputated spirit. There is no prosthetic for that."). Truly, the heroes (Pacino and Simms) come home with this magnificient speech!
# As an aside, on the business side, "Greed is Good" (Douglas, Wall Street) of course rules. Douglas' effortless simplification of world in which we live in, stands true probably today as well.