Corn Tortillas Vancouver
Que Pasa (they sell everywhere, but they have their plant in Richmond where you can get fresh tortillas - phone to see if they still do that.).
EL Surreno on Commercial
Los Guerreros on Kingsway
Also - if you phone ahead, you can order fresh Masa from South China Seas Trading (Granville Island and also Victoria Dr). You can also get fresh masa from the other stores listed above, but phone ahead to check availability.