Taco trucks are what kicked off the food truck craze to begin with so it's only natural that there would be plenty to choose from.
Food trucks tend to offer tacos in all kinds of interesting varieties. That's not to say that there aren't any traditional Mexican food trucks either. You can also find foods from other cultures like Venezuelan or Brazilian.
They usually offer a variety of favorites like tacos, enchiladas, burritos and more. Vegetarian and vegan options tend to be available as well depending on the food truck.