For basic tacos, burritos, sopes, tortas, and huaraches, I recommend Pico Pico Rico at Magnolia and Kester. It's mainly just a stand with a few tables, and can be maddeningly inconsistent, but when it's good, it's very good. When good, the asada and carnitas are very flavorful and the tortillas are hecho de mano.
El Jerezano is similar, but it also can be inconsistent.
My best bet for a consistent taqueria is to get on the 134, go to Cahuenga and get tacos (and kick-ass salsa) from El Taco Llama. But Pico Pico Rico is my current go-to when I need a taco fix.
Tony's Grill is wonderful. They serve light, fresh Mexican dishes with an emphasis on fish. The chips and salsa, chili rellenos, tortas, fish tacos, burritos and combo plates (with whole pinto or black beans) are all wonderful. The smoky, spicy, fish soup is also a standout. Plus every meal comes with a free fruit salad, topped with a dab of vanilla yogurt for dessert.
Be advised, Tony's is in a strip mall, so if you're looking for fancy, this isn't the place. But if you want superior, reasonably priced Mexican food, look no further.
La Fogata is also good. It's nothing like Tony's but the So-Cal-Mex food is good. Again, this place is not fancy.
While Senor Fred gets mixed reviews on the board, I have had good luck with their dinner specials menu, which never changes, but they are the non-traditional dishes like Cochinita Pibil, a very good salmon dish, lamb shanks, etc. Also a tasty crab enchilada. I do not dislike the other items, yet others seem to, but they are light years better than at the vega down the street. Good margs btw.!
www.senorfred.com for deets.
Other places in the area would include La Fogata on Van Nuys, El Ranchito on Ventura near Noble, El Torito and El Torito Grill( in the galleria), Mexicali Cantina in Studio City for decent food and better margaritas and a heavy helping of noise, Ernie's on Lankershim, Henry's Tacos on Moorpark, Bronco on Moorpark at Woodman, Tortas Mexico on Ventura near Vineland. Most of these have their attractors and detractors.