If you take Kirkwood north from my place, right before you hit I-10 you will see a Shell on your right and a Citgo on your left, literally across the street from one another.
The Shell is nice, clean, bright, well-lit, and almost always busy.
The Citgo has two broken windows covered in plywood, and the plywood is covered in graffiti. There are more lights out than on. Four of the eight gas pumps have OUT OF ORDER signs on them. The only people I've ever seen at the Citgo are of the type that instantly make one think "thug."
I know exactly where you're talking about. I've been to that Shell station many times. (And that Starbuck's right there in the parking lot next to it.)
I've never been to that Citgo. It always kind of gave me the creeps.