Cantina Lounge on Nutwood and Commonwealth in Fullerton has a three taco for $2 deal! No minimum drink purchase required! The tacos are small, but are packed with meat. They give you free chips (pretty good quality, somewhat dry) and delicious salsa with large chunks of sweet tomatoes, onions, cilantro, and diced Jalapenos. Most importantly, the quality of the taco fillings is better than at most Taquerias! Carne Asada was the best, followed by Pollo and Carnitas. The Carnitas were a bit too dry, however they were very lean-one thing I dislike about most Taco Tuesday carnitas are the globs of fat attached to them!
Taco Boy on Euclid between Orange and Ball has 75 cent tacos, plus they're open until Midnight! They have all of the usuals: carnitas, lengua (tongue), pollo, asada, chorizo, and pastor. I think the pollo is the best. It's marinated (mostly) white meat, very tender and tasty. Carnitas and chorizo are a bit more variable but can be quite good. The pastor is good but is sometimes dry and/or fatty. The carne asada is a bit tough and also sometimes fatty but can also be pretty good. Their horchata is creamier and has more cinnamon than the watery versions found at most other taquerias i.e. Festival brand. They also have fairly good dulce tamales, tinted a nice shade of pink, with a sweet coconut flavor, also not that common at other taquerias (my favorite are at La Casita LC in Orange, El Gallo Giro in Santa Ana, and Los Golodrinas in Laguna Niguel).