I ran into Chowhounds shadrach and M. at Ba-Le today. Over banh mi, they asked whether I knew where they could find top-notch tacos de lengua (one of their staples when they lived in Chicago, apparently).
I told them that I thought I realled lengua at El Charrito Caminante. Indeed, how soon I forget: I deemed it one of my favorites there two years ago. (see [BROKEN LINK REMOVED])
Roe liked it at TECC, too --check out the long thread linked below.
Does anyone know any other places with great tongue tacos? The taco truck on Broadway in Baltimore is rumored to have a superior version, and I'll bet one or two of the Bladensburg Avenue locales does, too.