3014 W Olympic Blvd.
The food is outstanding, genuine Mexican fare - not the Cali-Mex stuff which nearly universal in California, even at the mom-and-pop hole in the wall type places. Don't get me wrong, Mexi-Cali is really good, too - but it's not like Guelaguetza, which is much more varied and interesting than just various kinds of burritos. I had a combination plate of various mole's and meats, with flour tortillas and some little pickled vegetable salads that I can't identify but packed a serious punch. And all at a really low price.
The food is reasonably prices ($10-$15 per entree) with a decent and really cheap wine list. This is one of my favorite places in LA (challenged only by Versailles, La Frite, and Fukyu Sushi)