There is lots of great food in Houston!
If you want something quick where you can also enjoy Herman Park, check out Torchy's Tacos in the Village.
You also can't go wrong with Pappas, although I prefer Pappas Seafood.
Taste of Texas has an awesome salad and soup option (the salad bar is amazing), but like other posters say, it is not close to the airport.
Are you flying out of Hobby or IAH? There are not many restaurants near Hobby, so you will definitely want to stop somewhere before you get there.