Movies are the great social inequalizer.

Most people don't like to discuss movies.  Don't get me wrong--everyone loves to talk about movies.  After seeing a movie, however, most people have made their judgement and no longer need to receieve any additional information about it.
If we bring up a movie we've seen in a conversation, it's usually only to see if the person we're talking to agrees with us.  Example:
PERSON 1: Hey, did you see "Brain Candy?"
PERSON 2: Yeah, that sucked.
PERSON 1: Oh, I thought it was really funny.
PERSON 2: [looking repulsed] Really?
Of course, Person 1 immediately assumes Person 2 has no sense of humor and their taste is, from then onward, in question.  Person 2 wonders what the hell Person 1 was on when they saw the movie.  Of course, neither of these people really want to talk about the movie in question--that would waste a lot of valuable Simple Personal Judgment Making time.
I use "Brain Candy" as an example, because it's the sort of film people seem to either love or hate.  But what if, say, one of the two people actually is interested in the other person's opinion of a film?  What if they want to try to understand them?  Let's take another movie everyone seems to split on, David Cronenberg's "Crash."
PERSON 1: Hey, did you see "Crash?"
PERSON 2: Yeah, that was like the worst movie EVER.
PERSON 1: Why did you think so?  I felt it was a fascinating examination of the shallow pastimes people use to fill up their lives when real emotion is sadly lacking.
PERSON 2: [looking confused] It was just boring.  And it sucked.

Person 2 then makes the judgement that Person 1 is the type who can't enjoy movies without analyzing them to death, and realizes they shouldn't ever, ever hang out with a film major again.  Person 1 has made the judgement that Person 2 is an idiot.
Of course, not all movies are controversial conversational topics.  If you're trying to agree with someone in the hopes that they appreciate your great sense of cinema, be sure to mention "Reservoir Dogs."  Quentin Tarantino backlash may be popular, and everyone seems to enjoy a good joke about "Four Rooms," but "Reservoir Dogs" mas managed to remain blemish-free.
The reason for this is that, simply put, it's something everyone can agree on.  Film geeks love it.  Frat boys love it.  Hell, your parents probably thought it was great, but they probably didn't tell you.  It's got great dialogue, great acting, loads of violence, a healthy dose of mascocism, a well-placed soundtrack and it's non-linear enough to be interesting, but not so all-over-the-place that someone who only pays passive attention to the films they see can't follow it.
"Pulp Fiction" doesn't work nearly as well for several reasons, but one in particular.  "Dogs" was a small, independant production that was virtually ignored at theatres and acheived cult status slowly after reaching video.  "Pulp" was a big blockbuster hit, nominated for several Oscars and everyone saw it within a year after it came out.  Simply put, there's been plenty of time to hate "Pulp Fiction."  There may be some "Dogs" backlash eventually, but it will probably pale in comparison to the number of people who hate "Pulp Fiction" now.

Comparing films you enjoy can be a good way to get an emotional connection with a person.  Even more radical a concept is to compare film opinions with someone as a way of getting to know them.  Here's another example, this time using Paul Verhoven's "Starship Troopers."
PERSON 1: Hey, did you see "Starship Troopers?"
PERSON 2: Yes, and I enjoyed it. I thought it was a clever satire on both warfare and the racial and social class divions become more evident in America.
PERSON 1: Really?  I felt the satirical aspect was lost in the translation, and instead we were given poor characterizations without a hint of irony.
PERSON 2: Interesting.  Well, at least Denise Richards got naked.
PERSON 1: Yeah, that was cool.

And this, my friends, is the beginning of a beautiful friendship.  So next time you talk about movies to a total stranger, try to think of something interesting to say.  Other human beings are actually fairly fascinating if they use their brains once in a while.