Seeing how I live and Dallas and Lived in Houston for 30 years. I'll chime in with my War and Peace.
Mexican food is better in Houston. Still trying to find something that compares in Dallas. Dr Freeze is pretty much on with the Lupe Tortillas fajitas being the best ever invented. Red Onion is also retarded good and for my money better than Americas if your into South American. I'm not a big Cafe Adobe fan and don't go to the one on Westheimer on Monday or your likely to have to explain a lot of things to your kids in the same sex mating education area. Can't go wrong with Pappasitos (Dallas or Houston) very very good but somewhat pricey for Mexican. If you have kids stay out of El Patio at all costs as the food is marginal at best, and once again the kids are likely to see things they shouldn't after the everclear margaritas start flowing out of "club no minor". If it's a week night El Tiempo on Richmond has really good food, but the bar crowd will probably be too much on Friday or Saturday.
As for Dallas, Probably just go to Pappasitos or there is a new place called Manny's that is real good, but can get pretty crowded. If your stuck their are 15 Mi Cocinas that are decent, and if you want South American Gloria's is okay. If you want high end authentic Mexican Javiers is very good but is stupid expensive and you may need a reservation.
On to steaks. Both Dallas and Houston have good steaks, and you can pay whatever you want. I can name 10 places in each city that have great steaks, but are high end and less kid friendly. If you've never been I'd recommend Fogo de Chao in either city, but be prepared to get the meat sweats as it's an all you can eat Brazilian Churrascaria, but oh how good. If not, in Houston I'd go to Taste of Texas as it's as good as any high end restaurant and is alot more laid back and family friendly. In Dallas you can't go wrong with Bob's Steak and Chop house, Del Frisco's, Nick and Sams, or Kirby's (but all are very high end).
If while in Houston you decide to taste some Texas style BBQ brisket for lunch or something, try either Goode Company on Kirby, Otto's on Memorial, or Luling City Market on Richmond. All 3 places have greate food.
As far as attractions for the kids I'll probably should pass on this one, but in Dallas (arlington actually) you have Six Flags, and the Aquarium in downtown is pretty cool.
So basically. I'd definitely Go to Lupe Tortillas and order the beef fajitas in Houston. If you've never had all you can eat Brazillian churascaria eat at Fogo (wife will like the Salad bar). Other than that any thing in the list above is good. If you want get my email from Jack and I can give you other suggestions. I'll also be at the June 30th game. I'll be the dumb ass in the Bob Knepper jersey.
