[Vicious108]

Any speech by the aforementioned Griffith (Berserk) and the Major (Hellsing Ultimate).

Also, this speech from Kenshin to Tomoe (Rurouni Kenshin):

Spoiler:

"I was born into poverty, worrying about food every day. I lost my family. And at ten years old I found myself training relentlessly in Hiten Mitsurugi Ryu. And now, I am a Hitokiri of Choshu. I've never initiated a conversation with anyone. Never exchanged smiles. Alone but for Hiten Mitsurugi Ryu, my sword and death... I journey ceaselessly towards the new era where every man can find happiness. But in truth, until now, I had no idea what this "happiness" really was. Five months of living here in the farmlands, with you... has shown me what I've been fighting for. What I must keep fighting for."

And this chilling Hannibal Lecture by Solf J. Kimblee (Fullmetal Alchemist):

Spoiler:

"To seek justice in a special place like a battlefield is what's strange. Is it heretical to kill with alchemy? Is it better to kill with a gun? Or is it that you were prepared to kill one or two, but can't bear killing thousands? When you wore this of your own will, weren't you already prepared? If you don't like it, you shouldn't have worn it in the first place. You moved forward onto this path on your own, why are you playing the victim now? If you're going to take pity on yourself, don't kill people in the first place. Don't avert your eyes from death. Look forward. Look at the people you're killing in the face. And don't forget them. Don't forget. Don't forget. They won't forget you either."

As well as this crazed speech by Caster (Fate/Zero):

Spoiler:

"At this banquet of death and decadence that I, the humble Gilles de Rais, have prepared, everyone may have their fill! Now let us once again raise the flag of salvation! Gather here, O abandoned ones! I shall lead you! I shall command you! The deep resentment that we, the oppressed, hold shall reach God himself! O God in heaven, with words of condemnation I praise your holy name! Arrogant God! Cruel God! We shall pull you down from your throne! O lambs loved by God! O humans who take after the image of God! At this very moment, scorn, insult and tear apart to your heart's content! We will ride on the guffaws of the rebels and on the lamentations and shrieks of God's children and strike down the gates of heaven!"

And many others I happen not to have transcribed.