West side is always nice. Below around 17th is a lot of businesses getting to a crappier area below 14th (now in center city.) East side is widely inconsistent if it's nice or not you'd have to drive around but I know that's where I apparently some people bought heroin in the 00s.

South side can be nice as well.

Now there's been some gentrification and I've only driven through it since then. Bethlehem is a real nice place too, but there are all sorts of places to live in the valley.