The Wall Street Journal

***This airport gift shop is a clean and fairly big one with good and friendly service; in addition to magazines, toiletries and earphones, this store has a wide variety of bottled water and snacks (including healthy though expensive options)***
This store is located past security so it is only open to air travelers. I am not sure what the parking situation is at Houston International Airport, but I imagine the parking here is expensive like other airports.

The cashier was friendly. I popped in to buy a postcard. They had 4 to choose from so not the biggest selection (this is just a small store) but I had already looked in several other larger stores with no luck.