As a certified child passenger safety instructor (for 12 years now), it's very important to find a car seat that fits properly into your vehicle. Use a type of seat that's appropriate for your child (convertible rear-facing for children as long as possible - some now go up to 40 pounds RF, THEN transition to a forward-facing position, five-point harness as long as possible before moving them into a booster seat) and make sure the seat you choose can be used correctly by every member of the family/caregivers who will be transporting your child.
MANY of the manufacturers are using extensive technology to improve their side-impact protection. As you're in Houston, you have access to a wide group of child passenger safety instructors and technicians, in fact, Baby's First on Westheimer has one on staff. Take the time to speak to someone who's knowledgeable about the proper installation - and ALWAYS read the instructions BEFORE you start using the seat. Texas law mandates that all child safety seats must be used according to the manufacturer's instructions - if you haven't read them - how do you know you're following their requirements? Take the time to do test installations before you purchase the seat - that way you can weed out those that don't fit properly in your vehicle. Also - remember that seats do have expiration dates - you may not be able to use certain seats up to their maximum weights if the expiration date comes before your child has met the weight/height limits. Typical expiration dates are 6-7 years from the date of manufacturer - not from the date you start using it. One manufacturer has a 9 year date for the backless booster phase of their seat and a 10 year expiration date for their newest seat on the market.
Good luck!