Not just they're songs but some of the things they've said to people as well. Quotes as well as lyrics, as it were:
"Stay beautiful, keep it ugly" - Gerard Way (Lead singer)
"I am not afraid to keep on living, I am not afraid to walk this world alone" - Welcome to the Black Parade
"You gotta be what tomorrow needs" - SING
"I mean this I'm okay" - I'm not okay
"Gravity don't mean that much to me" - Bulletproof Heart
"You only hear the music when your heart begins to break" - The kids from yesterday
"This is a band that will save your life" - Frank Iero (Guitarist)
"The only hope for me is you alone" - The only hope for me is you
"I'd like to send a message to all the ladies. If a guy comes up to you and offers you backstage passes if you show him your t**s, I would like you to extend your arm, raise your middle finger, spit on him and say F*** YOU!!" - Gerard Way
"Truth is now acceptable" - Planetary GO!
Editor's note: Edited to put in the video of "Teenagers".