Need recommendations for food

Hello, I'm meeting with some family in the southwest part of Houston near sugarland. My mum has a couple of requests if one of you could help me out 1. A good authentic Mexican restaurant 2. A classic American diner for breakfast (country fried chicken is a plus) 3. A great barbecue spot (not overpriced nonsense) 4. A restaurant that screams Houston Thanks so much in advance

*edit forgot east and west directions