I took a general Pop Culture class my first year of college and we took a day to talk about quotes and their significance in pop culture. Based on the stuff said in that class, I think this is an excellent list of quotes that had an impact on pop culture, not just cool quotes in general.
As far as the Star Wars quote goes, I agree, it should definitely be here. I actually just finished up a Pop Literature class where we read a book called Sex, Drugs, and Cocoa Puffs. It basically analyzes the importance of pop culture. One chapter was specifically about Star Wars and since my prof was a big Star Wars fan, he discussed how that particular scene had a huge impact (pop culture-wise) on his generation and was probably the defining pop culture moment for people his age. Of course, he is a bit biased.