Of course, the "Thursday" up there is misleading; just about any day could be a taco truck day around here. The stretch of Roosevelt Avenue in Queens between 75th and 83rd Streets houses at least seven taco carts trucks, along with several other carts purveying various other (mostly) Mexican delicacies. They're all worth at least one try, but the best of the taco vendors is Tacos Mi Mexico Lindo, located at the SE corner of Roosevelt and Baxter in front of a bank. There's usually a crowd, although if you go on a cool night (or in the winter, but eating at a cart is really not fun in the winter) it is generally quieter. This is not fast food, but it is very, very good food.
What's to like? Start with the vendors themselves: three Mexican ladies, possibly sisters or possibly not, who will assume that you speak Spanish until proven otherwise. They do speak a bit of English, but make the effort - it's fun ordering in the appropriate language, and your vocabulary really won't be tested much. As a crash course, "para llavar" means "to go", "para ca" means "to stay", and "con todo" means "with everything" (usually referring to cilantro, onions, and guacamole on your taco). Tacos can be had with several meats: steak, chicken, chorizo, carnitas, and al pastor are all options, as well as a few more interesting and better ones I'll get to shortly. The tortillas are briefly heated on the griddle, which really brings out their flavor, and they meld with the tacos much better than a regular corn tortilla right out of the bag. They're also double-wrapped, which I've always been a fan of - especially when you're dealing with the kind of somewhat-overstuffed tacos to be found here.
Back to the meat: we'll start with the losers. The pollo, bistec, and cecina are probably not worth your time, unless you like your meat dry and chewy. I know cecina is supposed to be dry and chewy, so maybe it's just not for me. The other two? Just skip them. The carnitas was not crispy enough the first time I had it, but I had another one a few days ago and it was absolutely perfect: crisp on the outside, the larger pieces softer on the inside, and smoky from the initial frying and the reheating on the griddle. For me, the top choices are the chorizo, lengua (beef tongue), and oreja (pig ear) - all are superlative, really the best I've ever had anywhere. The chorizo is rich but not too rich, generally crispy from the griddle, not too salty, and has great pork and chili flavor. The lengua is very fatty but incredibly flavorful - like the carnitas, it's crispy outside and softer inside, but the pieces are bigger to give you a better contrast. The oreja is somehow the richest of the bunch, although I suspect it's rich in the way that tendon is, since I didn't think there was a whole lot of fat in a pig's ear. They cook it so long that the cartilage almost melts away - if you've had pig ear as an appetizer in a Chinese restaurant, this is nothing like that. It's not crunchy at all, more silky like tendon is when it's cooked well. The standard toppings are cilantro, onion, and very good guacamole - on the bar, there are also two chili sauces (the red is garlicky and particularly good), lime wedges, onion and jalapeño relishes, dried red chilies (sensing a theme here?), and radish slices - these seem to be typical accompaniments at all the carts and trucks in this neighborhood.
If you don't want tacos for some reason, the quesadillas are equally good - this is a Mexican-style quesadilla rather than an American or Tex-Mex one, so it is one larger tortilla crisped up on the griddle and folded in half over a filling of meat, cheese (I think it's Oaxaca cheese), and crema (basically Mexican creme fraiche, as far as I can tell). Other toppings are up to you from the same list as the tacos'.
If you're feeling vegetarian, the sopes are great as well. They used to use regular corn tortillas, but they switched a few months ago to thicker masa "cakes" that are ridged at the edges to avoid the filling falling out. The price went up too, but it's worth it. You can get these with meat, but I like them "regular" - with beans, creme, and a grated hard cheese of some sort.
As I noted earlier, this food is not fast even though it's from a cart - 15 minutes was a routine wait when it was warm last fall, and for all I know it could be even longer in the summer. You can get your food in 5 minutes in the winter, but it's best to eat at the cart, and food gets cold really fast in the winter. It's more than worth the wait, though.
Tacos Mi Mexico Lindo
Southeast corner of Roosevelt Ave and Baxter Ave (in-between 83rd and 84th Sts)
Open every day of the week, from midmorning to at least 11pm
Tacos: $2 each
Quesadillas: $3 each
Sopes: 3 regulares for $5