Taqueria Vallarta Jalisco, on E. Riverside, (I think the cross street is Lakeshore blvd.), is open until 2:00, 3:00, and 4:00 a.m., depending on the day of the week. The food there is solid and inexpensive Tex-Mex, and their cilantro-y salsa is great. The servers probably won't speak English, but menu items are numbered for ease of ordering. They also have a drive-through window. It's a hole-in-the-wall type of place, but if you're in the mood for that kind of food, you will probably leave satisfied.