Archer's final speech towards the end of "Terra Prime" is excellent.
Up until about a hundred years ago, there was one question that burned in every human, that made us study the stars and dream of traveling to them, Are we alone? Our generation is privileged to know the answer to that question. We are all explorers, driven to know what's over the horizon, what's beyond our own shores. And yet, the more I've experienced, the more I've learned that no matter how far we travel, or how fast we get there, the most profound discoveries are not necessarily beyond that next star. They're within us, woven into the threads that bind us, all of us, to each other. The final frontier begins in this hall. Let's explore it together.
TNG: Q Who?
Q: If you can't take a little bloody nose, maybe you ought to go back home and crawl under your bed. It's not safe out here. It's wondrous, with treasures to satiate desires both subtle and gross. But it's not for the timid.
http://www.imdb.com/title/tt0708758/quotes?qt1011107