Close to train
I get together for lunch with a group of 10-20 people, some of whom don't have cars, so we try our best to find restaurants within walking distance of a train. We live all over L.A. Our tastes are fairly eclectic and the top budget is around $12-13/person. We are running out of new places to try. I am tired of too sweet Thai.
You might want to try a search for "Red Line," "Blue Line," "Green Line," etc. as there have been some threads that mention restaurants near those lines / stops. Here's one for the Gold Line (note that it was started in 2007 and that you'll need to look into what's still open): http://chowhound.chow.com/topics/436841