The Archetypical Los Angeles Food Experience
It's a tough question. The archetypical LA Food experience is like LA itself--multifaceted and sprawled out in many different directions. It doesn't always mean the best meal. I would vote for these:
1. The special burrito at El Tepeyac in East LA. This is a classic example of a California-Mexican dish. The ingredients are mostly Mexican. The size and presentation are clearly Californian: immense and over-the-top.
2. Dim sum at 888 restaurant in Rosemead. They serve cart-style dim sum, which is something that pretty much disappered from Hong Kong or Guangzhou many years ago. It's a superb example of how immigrant communities cling to customs that no longer exist in their place of origin, which pretty much describes most people (including those from the American Midwest) who have come to LA.
3. In-N-Out Burgers: about as So Cal as it gets.
I like how Das Ubergeek put it in this reply:
"Also, just a slight complaint about your assumption that Los Angeles is
only movies and blondes. That's the image projected out to the world,
and if you never leave Hollywood or the Westside you could maybe be
excused for that worldview, but Los Angeles isn't principally that;
it's a huge melting pot where people eat "foreign" cuisines as easily as
they eat their own, where you'll see Korean-speaking Latinos in Korean
restaurants and Chinese-speaking Caucasians in Shanghainese places. That's
Los Angeles's culinary identity to me."