Ah, my sister and I do this all the time. We had a penchant for quoting movies when we were little, and it's stuck. The big ones lately have been:

1. "I can just imagine." (John Adams, in 1776 - notably because he says "uh"magine rather than "i"magine.)
2. "You have NO idea." (Trekkie Monster - Avenue Q)
3. "That'll do, pig." (Babe)

There are plenty of others, but I can't place them right now...