If you want to get a bird's eye view of Houston, nothing will provide that view to you better while keeping your feet firmly planted on the ground than the JP Morgan Chase Tower observation deck. Chase Tower is 75 stories tall, making it the largest building in Houston and one of the 10 largest buildings in the United States. Open weekdays from 8am to 5pm, you'll get an incredible view of Houston's skyline.
Don't worry about needing to bring cash with you to get this unique glimpse of Houston – it's free! All you have to do is walk into the tower and take an elevator up to the 60th floor. There are even some elevators that go straight to the observation deck! There are bathroom facilities up on the observation deck, but there really isn't any place to sit to contemplatively enjoy the view.
If you're brave enough, go up to top floor and take a look through the windows of the reception area of the law office that occupies the 75th floor. Just keep in mind that you may be asked to politely leave once they figure out you're there for the view and not for legal representation!
Once you've experienced Houston from above, you can also experience it from below. The Chase Tower is connected to the underground tunnel system of Houston and there are plenty of shops and small food stands to explore.