Yup! We like it. There's a nice restaurant, very neat theming and environment, the shark encounter ride is cute (not worth a long wait, but it is worth a short one), and the walk-through aquarium is easily worth the $7 or so admission. If that's your kind of thing, it's worth a visit.
The Museum is also very nice in Houston. They've got a beautiful butterfly pyramid which is worth a walk-through, a nice IMAX screen that usually has good shows, a planetarium, and a pretty good Natural History museum, all linked to the same complex.
The zoo isn't bad, but if you're coming sometime soon, it's been way too hot to enjoy, or I personally think so anyway.
If you want to run down to Galveston, Moody Gardens is a fun stop.