Williams Tower by the Galleria (both the tower itself and the waterfall); view of downtown from Allen Parkway; the Heights.
Let us know what else you come up with.
Anything around Galveston, NASA centre, downtown... basically all the tourist locations!
Also local parks (recreation areas) the zoo, and earlier on in the year, the childrens festival
Those are the places I took pics of when we visited there earlier this year.