The Best place is a real Taqueria named Los Tres Amigos.
The entire place seats about 35 people, but the food is beyond question as to authenticity and quality. Prices are fair to good. 2 Enchiladas, Chile con queso and guacamole with rice, refried beans & drink for about $6.
If you're in there, say hi to Juan, the Owner. (I eat there about three days a week.)
From The Woodlands, take Woodlands Parkway over I-45. It will be on your left in the shopping center. It is technically in Oak Ridge North.
From the mall, exit 45 and take the exit for Robinson Road/Oak Ridge North to wrap around and over the bridge.