Last weekend Derek and I went to the Cockrell Butterfly Center, which is a part of the Houston Museum of Natural Science. I think it was a good experience for the price, which was $9 a ticket, and Derek got in for $8 when he showed his school ID.
The main section, where the butterflies are, is a large glass dome that is a few stories high. An iguana and a few turtles live among the butterflies too. There are also two small exhibits though, one about being an entomologist (one who studies bugs), and another where there was various bugs on display (thankfully) behind glass.
There were so many butterflies! Every time you turned around you saw a different one. Lots of different colors and species. I enjoyed getting use out of my macro camera lens.