Right, I'd better see what I can come up with for my list!
Part 1, because only being able to take a maximum of 5 media posts isn't entirely helpful for this sort of discussion:
1. Bilbo meets Smaug (
The Hobbit: The Desolation of Smaug)
Bit of a cheat perhaps as it features exchange of words with Bilbo as well as Smaug voicing his thoughts aloud, but others have included speeches featuring interplay between characters as well (such as
300's "Spartans, what is your profession?" and, also one of my own selections, the Tragedy of Darth Plagueis the Wise), and given that Smaug (figuratively and literally) fills and dominates the scene with his presence, I'd take a harsh judge to disqualify it. A classic moment in the Hobbit novel brought to live excellently by the talented performances of Martin Freeman and in particular Benedict Cumberbatch, who gives the dragon both a larger-than-life ego and his sinister intelligence and menace.
2. The Tragedy of Darth Plagueis the Wise (
Star Wars: Episode III - Revenge of the Sith)
Palpatine's illuminating monologue of the life and death of his Sith Master not only gives us great insight into the culture of the Sith in comparison to the Jedi, but is also instrumental in swaying Anakin's loyalty into the favour of the Dark Side of the Force.
3. I will have my Vengeance
(Gladiator)
A classic moment from an all-time great, as the deeds of Joaquin Phoenix's pompous and egotistical Commodus come back to haunt him when he demands one of a group of gladiators take off his helm.
4. The Birth of the Galactic Empire
(Star Wars: Episode III - Revenge of the Sith) A short one given that the scene starts halfway through Palpatine's address to the Senate, but still one that resonates with me in particular as a landmark moment in the Star Wars story that echoes the history of Ancient Rome, as Palpatine weaves lies of a Jedi assassination attempt, proclaims himself dictator-for-life and proposes to change the divided Republic into a Galactic Empire under his sole effective rule, and, ignorant of the alarm bells this would normally ring, the Senate wildly applauses and welcomes the decline of the galaxy's freedoms in the hope of security after the tumult of the Clone Wars. It's the moment we really see things shift from the Republic era of the Prequels to the beginning of the Empire era that is to, in time, trigger the events of
Rogue One and the Original Trilogy.
5. Adama's First Speech after the Cylon Attack (
Battlestar Galactica 2004)
In case you haven't seen it, the 2004 reimagining of Battlestar Galactica features a lot of speeches amidst the internecine brawls, battles against the Cylons and intrigue as to who is a Cylon infiltrator and who is not, and it's this one that sets the precedence of the whole series - it outlines the fight for survival that is to come as the survivors of Caprica flee to find the legendary 13th Colony after the Cylons return with a vengeance, and the unity, cooperation and grit that are required if it is to succeed. So say we all!