I'll proffer the things that have come out of my current home town for American cuisine (my real hometown hasn't contributed much except some football players and indoor foliage)
- The chili size - Take a bowl, add some chili, add a griddle cooked hamburger patty, add more chili and cheese. Serve - an LA classic
- The French Dip - Hotly contested between two locations here in downtown - the French Dip was invented either at Phillipes, which is a funny old fashioned place to go grab a bite, or Cole's Pacific Electric Buffet. For my money, I prefer Phillipes and their devil mustard.
- The "LA" Chili Dog - There's a variant of hot dog chili that seems to be about 1/3 flour, meat, fat and tomatoes. Very smooth stuff, unlike any other chili I've seen on dogs. Best seen at Cupid's, Flooky's or Pink's (if you feel like waiting in line forever) (LA actually had a very interesting hot dog subculture)
- The BBQ Chicken Pizza - Invented by Ed LaDou while he worked at Spago's with Wolfgang Puck. Ed passed away sudddenly a couple years ago, but his little place Caioti Pizza Cafe still makes rocking pizzas and they have a salad called "The Salad" that some folks swear by to induce labor.
There are a few others, but how about the big mammer jammer that has unfortunately seated itself deep into the roots of the world.
- The Drive Through and the Fast Food Restaurant - McDonald's was born out in San Berdoo as was the drive through window at In n Out Burger (seriously fantastic fast food burger) Carl's Jr (owner of Hardee's as well), El Pollo Loco, Fatburger, Foster's Freeze, Green Burrito, Hot Dog on a Stick, H. Salt Fish & Chips, Jack in the Box, Johnny Rockets, Weinerschinitizel, Original Tommy's (oh god, the chili and grease), Panda Express, Taco Bell, Tastee Freez, Wetzel's Pretzels, wInchell's Donuts (and its owner Yum-Yum Donuts). - all LA region started fast fooderies that have been clogging everyone's arteries for a while now. Go LA!