It sounds as if you have a handle on the newer and more varied spots. If you want some old school Tex Mex, try Ciscos, Joe’s Bakery, or El Patio. A well known newer fave of mine is Chilantro. I love the bulgogi burger with caramelized kimchi and a fried egg. For BBQ I’d suggest La BBQ. For newer Mexican try Nixta or El Naranjo. If you want a sampler, the Royal Blue Grocery on Congress has Eastside Pies, various types of tacos, and more. For a BBQ and Japanese fusion, try Loro. For a greasy taste of old Austin, I love the Texas Chili Parlor and Dirty Martin’s Kumbak.