Modern Warfare 2 had some good ones
"The healthy human mind doesn't wake up in the morning thinking this is it's last day on Earth. But I think that's a luxury, not a curse. To know you're close to the end is a kind of freedom. Good time to take... inventory. Outgunned. Outnumbered. Out of our minds on a suicide mission, but the sands and rocks here stained with thousands of years of warfare... they will remember us for this. Because out of all our vast array of nightmares, this is the one we choose for ourselves. We go forward like a breath exhaled from the Earth. With vigor in our hearts and one goal in sight: We will kill him" - Price
"We are the most powerful military force in the history of man. Every fight is our fight. Because what happens over here matters over there. We don't get to sit one out. Learning to use the tools of modern warfare is the difference between the prospering of your people, and utter destruction. We can't give you freedom. But we can give you the know-how to acquire it. And that, my friends, is worth more than a whole army base of steel. Sure it matters who's got the biggest stick, but it matters a helluva lot more who's swinging it. This is a time for heroes. A time for legends. History is written by the victors. Let's get to work" - Shepard