I actually made this quote for a film we have been making but i decided to try it out in a linebattle and it certainly didn't make us fight any better, if there is anything there you disagree with, remember it was for a film not real life:
"Hold the line, hold the line and do not falter, for the good of the just and righteous, for the good of the most elite regiment in existance, for England, the land of the free! What is our policy?... To wage war against a monstrous tyranny, never surpassed in the dark lamentable catalogue of human crime. What is our aim?... Victory... Victory at all costs. Victory in spite of all terror. Victory, however long and hard the road may be. For without victory, there is no survival, all that is required is that you hold your ground no matter what happens, may they charge us head on, may they fire bullets and shells into our ranks, may they push us down, keep on holding this goddamn line and keep on fighting, fight now, fight now, fight for the man beside you, fight for mennas cookies, fight and die for honour, dead to the last man!"
Edit:
Used a few quotes from speeches and films here although most of it i made up, the main part i did use was one of churchills speeches, also got the last sentance "dead to the last man" from the last samurai, and got "fight for the man beside you... fight and die for honour" from immortals