If you are looking for a truely terrifying Haunted House in Houston, look no further than Terror Dome. This one might not be appropriate for young children, unless you want to mentally scare them for life.
They are located on East I-10 just outside of the Beltway. They are right next door to the Spookers Halloween Store, which is where you buy tickets before you get in line.
Tickets Cost $20 a piece, but coupons are availble on their website to save a few bucks.
The best night to go is Saturday or Halloween night, when they have the Live DJ and Zombie Dancers, makes for a very entertaining evenining, especially if you are with friends.