Oh yeah, absolutely do not go to Mi Tierra (San Antonio) for Mexican food. Tourists always get sent there but it’s a terrible example of Mexican cuisine. Find directions to Los Barrios.
Mi Tierra does not pretend to serve Mexican cuisine. It’s pretty good Tex-Mex–but gets extremely crowded at times. (You might drop by the bakery.)
However, San Antonio has about a million other options for Tex-Mex, Mexican cuisine, etc. It’s been years, but I liked Tomatillo’s, a big jolly place near Breckenridge Park. And there’s Rosario’s in the arty district. SA Dopers: If these places have gone downhill, warn us now! And suggest better options. This Houstonian might visit SA again some time…
Back to tourist sights: There’s a “petting zoo” at Fort Sam Houston.
There’s great Tex-Mex and there’s great Mexican.
The consensus here is that Mi Tierra is not even an option.
Tomatillo’s and Rosarillo’s are okay.
If I wanted truly corny Tex Mex, I’d go back to Casa Rio. My first & last visit happened on our family’s first trip to San Antonio.
That was back when Disney’s Davy Crockett was fresh on my mind. Although I found the Alamo impressive because it was this big ancient building in the middle of a city–That Battle was just part of its history. And, even as a kid, I thought the Alamo gift shop tacky but fun.
Damn, the International Accordion Festival is this weekend. Information on other SA festivals at that link. Now that the worst of summer is over, it’s festival season in Texas. Although San Antonio has no shortage of festivals/fiestas at any time.
Greek Funstival next weekend. Opa!
Don’t ask to see the basement, though!
Okay, I’ve heard this Alamo basement joke a number of times now. What’s the, er, straight dope?
Yes, I’ve watched John Wayne’s Alamo movie to get a sense of the history. And read De La Pena’s diary. I think I’m all set. 
It’s from the movie, “Pee-wee’s Big Adventure.” It’s where his stolen bicycle was supposedly hidden.
Removed double post.
The Alamo doesn’t have a basement BTW.
I see that Kimbell Museum was already mentioned as was Dallas World Aquarium, two of my favourites.
I guess I should also recommend The Dallas Museum of Art and The Nasher Sculpture Center.
If you want to eat tex mex in San Antonio, I would recomend El Jarro de Arturo, Rosarios, or La Fagata (more authentic Mexican, but with lots of tex mex options).
Or, if you’re not set on Tex mex, go to Chris Madrids and have a chedder cheesy. If you don’t have a heart condition before you set foot inside, you will when you leave, but it’s a hell of a good burger.
About an hour up I-10 is a little town called Fredricksburg. Very cute German town, worth spending a little time shopping. Eat at the Brewery (Mmmm, German food), buy some peaches, and climb enchanted rock.
I’ve never been all that impressed with the Alamo. The riverwalk is nice because of all the baby ducks (who probably wont be around this time of year).
Here is the deal about the Space Center. It’s a ways out there. From Bush airport you are looking at an hour and fifteen minutes to two hours drive to get to the complex (depending on traffic), another twenty or so minutes to park and get inside, especially if you aren’t familiar with Houston traffic. That said, it is definitely worth it.
I’m not sure how little your “little ones” are but there are plenty of attractions geared toward children. I’d also strongly recommend you take at least one of the tram tours if the kids are old enough to sit still for a tour type thing. They run different tours of different durations, depending on what is going on at the center, so its hard to say how long they take. Last time we were there we did the Mission Control tour and it took about an hour and a half. Also there is walking in many of the tram tours so keep that in mind.
I’d say you need at least a full morning or afternoon, five to six hours, to go out and do Space Center and get back to your hotel. (You’ll probably want to eat lunch there too). I think it is one of the better attractions for Houston visitors, and well worth it.
Also consider the Texas Renaissance Festival which is up and running for the season. It is the largest ren-faire in North America. It is massive and a real cut above the many of the smaller and cheesier versions found elsewhere. Its location in the middle of a dense pine forest gives it a special ambiance. It is loads of fun for a family. Again though, it is also located about an hour to two hours drive from center city so you’d be looking at a half day at least.
The two museums Bridget mentioned are also good choices for Houston with kids.
Do you know where you might be staying in Houston? Obviously it is a huge city, if you could narrow it down, or if you need more specific suggestions for restaurants or attractions in H-town I’d be glad to make suggestions.
Houston is the biggest city in Texas, yet it is the least interesting city for tourism. I’m glad you are getting the chance to do Dallas and San Antonio. I love those cities.
It didn’t cross my mind earlier, but Austin is pretty close to San Antonio and has a couple of thing worth seeing. If you get the chance, the Bob Bullock Texas State History Museum is worth the visit.
If you’re going to make a side trip to Austin, go visit the Texas State Capitol building. I’m pretty sure they still give tours and it’s just really cool. It’s HUGE(largest state capitol in the country) and really brings a sense of grandeur to those government lessons at school.
Enjoy,
Steven
For Houston:
In addition to NASA, you should spend some time in the Museum District and/or the zoo. If you like local history, check out Allen’s Landing - that’s where it all started back in 1836. And of course, there is the San Jacinto Battleground where Sam Houston kicked Santa Anna’s butt.
For eats - for a great casual meal, I strongly recommend Otto’s Barbecue on Memorial. If you want to drop some bucks and have one of the best steaks and overall dining experiences ever, you can’t beat the Taste of Texas.
When are you coming? Let me know and I’ll try to free up some time to buy you guys lunch or something. Especially if it’s at Otto’s! 
Hey, thanks for the offer, but we’re staying with friends who will take us places. We’re just thinking of the Space Center before we meet them.
I really like Fort Worth’s Log Cabin Village. It’s an assortment of real log cabins that have been moved into one location, with docents explaining how fibers were gathered and spun, how corn was milled, how metal was worked, etc. The docents also talk about the families that originally lived in the cabins. Good for adults and kids. I haven’t been to the FW zoo or the Water Gardens in years, but I used to really like them.
Houston - the butterfly arboretum. The ‘Aquarium Restaurant’ - if you like overprice seafood that is actually quite good and saltwater aquaria. It also has a ‘mini’ amusement park with a ferris wheel and a small train that takes you under the shark tank…
Depending upon what’s going on, Discovery Green park is pretty nice.
www dot discoverygreen dot com
Thanks all for your recommendations! We’re back and we had a blast.
Houston: Johnson Space Center and Chase Tower (60th floor observation deck)
San Antonio: Alamo and Riverwalk
Dallas: Dealey Plaza, State Fair, and the World Aquarium. That last one was a huge surprise. I wasn’t expecting such an extensive rain forest.
Fort Worth: surprisingly interesting; probably the most “Texas” of the four cities.
We ate our BBQ, Tex Mex, and Cajun food; all at excellent places.
But don’t take my word for it; take a look at the wonderful time my daughter Anya and baby boy Grant had: