Kyle, TX is a small town that is depressing as all get out. 98% of the houses out there came there on wheels. There's lots of green pastures, but they all have cow patties in them.
For Texas's bad areas: Houston and Dallas. Metropolitan shitholes.
Other states: I've been through most states in the Southwest, as well as several in the Northeast, and nothing really sticks out to me as particularly awful. I hated Las Vegas, but the lights were way too bright and I got a headache and I was 9, sooo...