I know this subject has probably been talked to death but i'm in the process of blogging my LA taco experience and I know the chowhounds here are wise men on this subject.
So far on my list i have
el gran burrito
la estrella (i plan on hitting up every truck in highland park)
la oaxaquena (venice)
la isla bonita (venice)
truck on western and lexington (no sesos for me tho :P)
any reccomendations would be welcomed.