Originality nowadays is a weird concept. We create every day such an amount of... well, anything! that it becomes hard to keep track of what's been done before, and what not.
I'd say that rather having an original line, it'd be more suitable to find an eye-catching phrase, regardless of it's contents originality. For example, I loved the invader zim quote and would be more positively inclined towards whoever arrived with that mindset!
Having said that, *gives a BIG nice cookie to Spirit*
:3 I know it's biased and I'm not supposed to do that, but anyone who arrives quoting Invader Zim has already gained three brownie points in my book.