They're all very friendly, but I do have to put in my vote that Mexico Puebla is the best. It says "Mexico Puebla" on the front of the truck and it is usually the first one in line. Yes, he also owns the last truck in line (yellow) which I suppose is the same quality food but rarely has a line. The first truck has the most traffic as you can tell by the crowds and the dirt patch out front. That should tell you something.
None are bad, but I have had burritos & tacos at Roberto's and at the Puebla and Puebla's are significantly better. Do a head-to-head comparison...the tacos are only $2! You can get one from each truck.
Here's the run down on the Puebla's food...
The carne asada is killer! Get it in the tacos or the torta. You get some tender flavorful beef with fresh toppings. Anyway...tacos in beef or pork, you can't go wrong! The chicken seems dry in the tacos but it is great in the burritos.
The chicken burrito is the bomb. I am always amazed how heavy the thing is when they hand it to me. For $6 they cram a lot of goodness in there. It has great flavor and is as big as a fully packed Chipolte creation. For some reason I don't like his carne asada in the burritos...I tend to find more tough pieces in a burrito, that I have no issue with on the taco. Go figure. If you like it spicy, ask for it very spicy! They have this really hot sauce they'll give you a cup of on the side that is delicious...it is different than the standard red or green sauce.
The tortas are excellent. There is too much mayo on there for me so sometimes I have them skip the mayo or add cheese....you get a carne asada torta with cheese and you know what you have? A mexican cheese steak! It's great. Flavorful beef, avocado, hot salsa...delicious.
The quesadillas are good if you like that sort of thing. I think they are kind of plain in comparison to the other items, but the quality is good. My kid likes them. The puppusas are good as well, but there are a lot of "pupusarias" in the area that do just as good of a job.
The "pitchman" out front of the Mexico Puebla is the owner. He speaks perfect English and is a really friendly guy. Talk him up and he'll tell you his life story. He says his tacos are "the best!" and he's right. ;)
Puebla was the first cart there 9 years ago. He used to run out of a little hot dog cart with his wife selling hamburger, hot dogs, tacos and burritos. The mexican food far outsold the standard fare so he saved up and bought a truck. Soon the success caught on and another truck or two showed up. He put a second truck in line because he was losing a lot of business since people passed one of the new trucks before they got to him. Anyway, that is some history for you. read more