Native Houstonian here. Still live here. Since it's so freaking hot here lately focus on stuff to do inside. NASA is great, great museum district, catch an Astros game if they are in town. DO NOT go to the Galleria mall. Galveston is dump. If you want to go outside the newly redone Memorial Park is nice and a stroll around Rice University campus in the Med center is an option. It's a beautiful campus. Crime has gotten out of control. As far as restaurant's there are so many it's hard to say but I like
Steak: Pappas Bro's downtown or Galleria & Vic & Anthony's
TexMex: El Tiempo,
Interior Mexican: Hugos, 100% Taquito
Coastal Mexican: Caracol
French: Etoile
Italian: Original Carrabba's on Voss or Kirby, Vincent's, Nino's, Amalfi
American: Houston's, Merus
Seafood: Goode Co., Willie G's
Sushi: MF Sushi, Azuma and a million others
Veitnamese: There are ton and most are great but Le Colonial is the best
BBQ: Truth, Pizzatola's, Pinkertons, Gatlins, Roegels, The Pit Room, Blood Bro's
And for the kicker: Our favorite place sans kids is Fuads. Dark bar / restaurant, quite, don't have a menu, just tell them what you want and they will make it. Ask for JR...................................