The fajitas and the fajitadillas (fajita-meat quesadillas) are made with sizzling, fresh-off-the-grill beef. The enchilada sauces are perfectly seasoned and never too thick or too watery. And giving away free chili con queso along with the chips and salsa at lunch hasn't hurt their popularity, either. The original Doneraki on Fulton had its fans, but the huge new location in the Gulfgate Center put Doneraki up there with the city's top Tex-Mex contenders. (A new Westheimer location is also coming on strong.) Tastefully decorated with saltillo-tile floors, Tabasco-colored walls and a huge copy of a Diego Rivera mural, it's one of the best-looking Tex-Mex restaurants in town. Like all classic Tex-Mex operations, Doneraki claims its chips and hot sauce, chile con queso, fajitas and cheese-stuffed jalape?os are "authentic Mexican." Bless their hearts.