For some reason, when I thought of pullling lines from CCS, all I could think of was "RELEASE!!!"
Sakura's "Zettai daijoubu!" is one of my favourite lines in anime though. And now that someone else has posted I can bring out The Drills!
"Don't believe in yourself. Believe in me! Believe in me, who believes in you!"
"Iika, Simon. Wasuren na. Omae wa shinjiro. Omae ga shinjiro ore demo nai. Orega shinjiro ore demonai. Omae ga shinjiru... OMAE WO SHINJIRU!"
"Believe in yourself. Not in you who believes in me. Not in me who believe in you. BELIEVE IN YOU, WHO BELIEVES IN YOURSELF!"
"ORE TACHI WO DARE DA TO OMOTTE YAGARU!!!!!!"
"WHO THE HELL DO YOU THINK WE ARE!!!!!!"
"[...] Diggin' a whole to pierce the heavens. Even in a grave I can dig on, and if I break through, it's my victory! Who the HELL do you think I am? I'm Simon! Not Aniki, Kamina, but myself! SIMON THE DIGGER!"
"MY-WAIFU-IS-THE-GREATEST-IN-THE-UNIVERSE-SWINGUU!!!!!!!!!!!!!!!!"
I know there is more Gurren Lagann epic quote-ness.