For a chain Ajo Al's is pretty decent. Shrimp fajitas, tacos morongo and fish tacos are all really good. All their taco plates come with great side sauces (tomatillo, chipotle cream, avacado puree). They also make a pretty yummy breakfast burrito.
I'm not a huge fan of their salsa, but they have a decent hot sauce. Their sangria is not actual sangria made with wine, but a fruit juice blended drink (beware). Top shelf margs are awesome.
The place is usually packed and I have always had great service.