Not sure if it's been mentioned already, but in Texas, I think Dallas' night skyline is the most striking. So many great lighting designs on their towers. Even their smaller buildings have some really nice lighting designs. Dallas' lighting designs really truly accentuate the building's unique designs. Oddly enough though, Fountain Place has no external lighting except for aircraft warning lights. Someone mentioned Houston already, and I agree their skyline is impressive at night (just saw it a few weeks ago and it's really impressive from the highways), but the lighting of their towers is very subdued. Even the tallest buildings have very little lighting. Even the most famously lit skyscraper in Texas, Williams Tower, only has a single beacon on the roof.
Dallas:
Photo by N1Spirit -
http://www.flickr.com/photos/1136766...42484/sizes/o/