We went taco truck tasting last night ...
(1) Sinaloa Taco Trucks and Taqueria International Blvd & 22nd Ave (excellent, good all arounder),
(2) El Novillo 1001 Fruitvale Ave, (in parking lot of Guadalahara Restaurant) great al pastor, great chicken (shredded ... yumm).
(3) El Ojo De Aqua taco truck Fruitvale Ave & E 13th St (ugg … not great, disappointing ... visible from El Novillo).
See http://www.chowhound.com/topics/450404 for a more detailed discussion of all things Oakland taco.
Any other recommendations?