Driving west down I-10, somewhere between the aptly named Flatonia and Seguin will have a pretty sunset.
You probably want a place that doesn t have so many trees. But that s probably a duh! for you already. I would stay nearer Katy where you won t have as many trees along the horizon. (The revolving restaurant in downtown Houston is the Hyatt. But you still don t see the sun go behind the horizon. You just see the sun disappearing behind buildings and trees.) Find a place you can see the actual horizon.
I agree with William K, go West. G. Bush Park is a nice place. Even SW over to the banks of the Brazos River, that could be a pretty place for a sunset.
or eleanor tinsley parkor the highest building in dowtown houston,i dont remember the name, but it has a revolving restaurant on the top.
yes thats a good place, i live in katy and it is not too far away and it is beautiful.