A good villain is what makes a better hero. It's common knowledge to wrestling fans- a great heel is what makes the crowd cheer for the face. So naturally, as times have progressed we have witnessed the birth of complex villains, often with monologues that are good enough to change the conviction of a layman. 

1. Agent Smith from The Matrix 

In the computer program, The Matrix, human beings were the virus and Agent Smith is what we could call the anti-virus. In the film series, human beings were the ones who ruined the planet by nuking it to block out the sun, believing that the machines ran on solar power. But the AI was able to adapt and then took over the world, replacing humans. 

Source: Matrix wiki

Simply put, humans started a war with the machines, destroyed the planet in the process and then lost anyway. 

You (humans) move to an area and you multiply and multiply until every natural resource is consumed and the only way you can survive is to spread to another area. There is another organism on this planet that follows the same pattern. Do you know what it is? A virus. Human beings are a disease, a cancer on this planet, you are a plague. 

                    - Agent Smith

2. Joker From The Dark Knight

In this scene, the Joker explains to Batman why they are the same, just freaks, who will be thrown away, discarded when people didn't need him anymore. And by the end of the film, that's exactly what they did. 

Source: Pinterest
You see, their morals, their code, it's a bad joke. Dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these... these civilised people, they'll eat each other. See, I'm not a monster. I'm just ahead of the curve.

                    - The Joker

3. Joker from The Killing Joke

Batman finds the Joker after the latter has completely destroyed Commissioner Gordon's sanity. When Batman finally finds him, Joker explains to him that he is no different than anybody else. All it takes for anyone to go insane is one bad day, even for the Batman. 

Source: Amazon
All it takes is one bad day to reduce the sanest man alive to lunacy. That's how far the world is from where I am. Just one bad day. You had a bad day once, am I right?... You had a bad day and everything changed. Why else would you dress up like a flying rat? You had a bad day, and it drove you as crazy as everybody else. 

                    - Joker

4. Reverse Flash from The Flashpoint Paradox

A depressed Barry Allen runs back in time to save his mom, but in doing so, he unintentionally distorts history. The world is about to end due to a battle between Themyscra and Atlantis. The following scene is where Reverse Flash confronts The Flash and asks him how he can call the former a villain when it was he who destroyed the world.

Source: Pinterest
And in a supreme act of selfishness shattered history like a rank amateur, turned the world into a living hell moments away from destruction and 'I AM' the villain?

                    - Reverse Flash

5. Colonel Nathan R. Jessep from A Few Good Men

Col. Jessep had given the order of Code Red that had led to the death of Santiago. In this scene, where he's questioned about the decisions he makes at Guantanamo Bay, Jessep, in rage, tells Kaffee how his men need to follow those orders to keep the country and people like him safe. 

Source: IMDB
I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the blanket of the very freedom that I provide, and then questions the manner in which I provide it. I would rather you just said thank you, and went on your way. Otherwise, I suggest you pick up a weapon and stand a post.

                    - Colonel Nathan R. Jessep

6. Bill from Kill Bill

When The Bride finally confronts Bill about trying to murder her, he tells her that one can't escape who they are. And the gives up the most most popular comic analogy we have ever seen. While his acts are still not justified, he does make a point. 

Source: Allocine
Batman is actually Bruce Wayne, Spider-Man is actually Peter Parker. When that character wakes up in the morning, he’s Peter Parker. He has to put on a costume to become Spider-Man. And it is in that characteristic Superman stands alone. Superman didn’t become Superman. Superman was born Superman. When Superman wakes up in the morning, he’s Superman. His alter ego is Clark Kent.

                    - Bill

7. Vulture from Spider-Man: Homecoming

When Peter tells The Vulture that it is wrong to make money by selling weapons to criminals, the latter asks him if he knew how his buddy Tony Stark pays for all the gadgets he has. Which makes you really question the actions of the Avengers, when you realise what mess they leave behind every time they fight. 

Source: LA Times
Those people, Pete, those people up there, the rich and the powerful, they do whatever they want. Guys like us, like you and me... they don't care about us. We build their roads and we fight all their wars and everything. They don't care about us. We have to pick up after them. We have to eat their table scraps.

                    - The Vulture

8. Bane from The Dark Knight Rises

Of course, Bane had ulterior motives, but while trying to achieve them, he gives people the truth about the lie that holds Gotham together. He destroys the image of their white knight- Harvey Dent, a madman who tried to murder Commissioner Gordon's family.  

Source: Cinemablend
You have been supplied with a false idol to stop you tearing down this CORRUPT CITY! Let me tell you the truth about Harvey Dent from the words of Gotham's police commissioner, James Gordon.

                    - Bane

9. Thanos from Avengers: Infinity War

At some point in the last two years, we have all agreed that maybe Thanos was right. And that just gone o to show that on some level, his reason for doing what he did was good. Resources are finite, people are not!

Source: Business Insider
Little one, it’s a simple calculus. This universe is finite, its resources, finite, if life is left unchecked, life will cease to exist. It needs correction... I’m the only one who knows that. At least I’m the only one with the will to act on it.

                    - Thanos

10. Alfie Solomons from Peaky Blinders

Enraged by the kidnapping of son Charlie, Thomas Shelby tells Alfie that he had finally crossed a line before putting a gun to his head. Alfie, then screams at Tommy because the latter himself had murdered countless families. 

They got your boy? AND WHAT FUCKING LINE AM I SUPPOSED TO HAVE CROSSED? How many fathers, right, how many sons, yeah, have you cut, killed, murdered, fucking butchered, innocent and guilty, to send straight to fucking hell, ain't ya? 

                    - Alfie Solomons

11. Amy, Gone Girl

While the movie was scary, it does present the reason for Amy's crimes. In this monologue, she explains why she was through with the woman Nick wanted her to be- the cool girl. 

Source: Babe.net
Cool girl never gets angry at her man. She only smiles in a chagrin loving manner and then presents her mouth for fucking. She likes what he likes. So, evidently, he’s a vinyl hipster who loves fetish monger. If he likes girls gone wild, she’s a mall babe who talks football and endures buffalo wings at Hooters...

                    - Amy Dunne

12. Cersei Lannister from Game Of Thrones

Cersei Lannister was a horrible person. Nobody is questioning that. And while we are all together in our hate for her, her monologue as she begins to torture Septa Unella is sort of cathartic considering what the nun had done to her just about a year ago. 

Source: Glamour
Confess. Confess. Confess. Confess: It felt good, beating me. Starving me. Frightening me. Humiliating me. You didn’t do it because you cared about my atonement. You did it because it felt good. I understand. I do things because they feel good.

13. Lucifer from Supernatural 

Sure, he is not as iconic as the other villains on this list. But he does make a point when Dean asks him what he wants to do and why he is hellbent on hating human beings. 

Source: Econotimes
I said, these human beings were flawed and murderous. And for that, God had Michael cast me into Hell! Now tell me, does the punishment fit the crime? Especially when I was right. Look what six billion of you have done to this planet, and how many of you blame me for it!

                    - Lucifer

14. Killmonger from Black Panther

Killmonger's father was murdered in cold blood by the kit of Wakanda because he wanted to help African American people who were facing racial injustice. So when he takes Wakanda and blames the monarch for not doing enough to stop the abuse of their people, he's not wrong. 

Source: Forbes
I want the throne. You are all sitting up here comfortable. Must feel good. There's about two billion people around the world who look like us and their lives are a lot harder. Wakanda has the tools to liberate them all.

                    - Erik Killmonger

Can't really choose a side now, can you?