Gridskipper, a helpful map-based travel site, has a list of the best Middle Eastern Restaurants in Los Angeles. Their list is OK but they've forgotten a couple of spots that really should be on there:
1. Sunnin Cafe. This Westwood hole-in-the-wall can be inconsistent but it's generally got the best Middle Eastern fast food in the city limits. The hummos is great, the spinach pies are excellent, and the kebab and shish tawaouk sandwiches are tops.
2. Carnival. A Valley restaurant that gets crowded with Israelis and Palestinians alike for a reason-- the food is good, the price is right, and everything is fresh and authentic.
3. Alcazar. I haven't actually been here but J. Gold loves it and it sounds amazing. Plus, they serve Arak.
4. Anaheim. There are more good middle eastern restaurants in Anaheim then all of Los Angeles combined.