Grilled Mexican meats - parrillada
I'm afraid you're mostly going to find Tex-Mex in north Dallas.
One of the very best is Casa Milagro on Campbell at Plano Rd.
Although, now that I think about it, you might prefer Cuquita's in Richardson on Spring Valley just east of Coit Rd. They're a bit closer in style to El Ranchito on Jefferson.
Cuquita's also has locations in Farmers Branch and Garland.