What part of the DFW area were you looking for? I am in the Allen/Plano area which is North of Dallas (just a 1/2 hr drive or less) and there are tons of things to do in Dallas as well Dallas is more "city" vs "country" feel. Ft Worth is more cowboy types.
All downtown Dallas area are:
American Airlines center, Dallas Mavericks, Dallas Stars, concerts, etc
West End
Dallas World Aquarium
Reunion tower
Science Center at Fair Park
Frisco has Pizza Hut park for soccer
Frisco Roughriders baseball
Allen has Allen event center, hockey
good shopping.
Ft Worth has a better zoo.
I was at the Stockyards once about 20 yrs ago and I was done.. nothing personal, I just don't get into cowboys and pick up trucks.
Sundance Square is kindof nice.
Arlington has Texas Stadium, Rangers, Six Flags, etc.
Great Wolf Lodge in Grapevine is a fun place for kids.
The Gaylord hotel is interesting
I don't know your price point on hotels. Embassy Suites (located all over) are usually nice and kid friendly.
As for San Antonio, again, Embassy Suites, the JW Marriott. Make sure you go to the riverwalk as well.
I book all hotels directly with the hotel website. It is also interesting to scan the Trip Advisor for reviews of the hotels you may select.
Enjoy your trip!!