My favorites would have to be the Tacos El pinolero trucks here in chico, there's a couple of them one's in the chico collision center parking lot and the other is in the parking lot on esplanade across from where the albatross was. They have the best steak there, as for chico I love the one on the corner of esplanade and shasta. It's a more permanant trailer type one.
I do enjoy the one inside dukes, they're pretty good as well. I actually just had taco truck today for lunch! It's cheap and good!