The dev stack I use changes a lot per project. Since most of my work is done as a consultant, I use whatever my client's current set up is for the most part. I like how that lets me try out lots of different ways of getting things done.
When it's up to me, I like to keep my dev stack as simple as possible. If I can get away with just Sass, autoprefixer, grunt, and minimal JS libraries, I totally will.
As for Pittsburgh hills, Squirrel Hill has the best name and Polish Hill is the most useful. A former co-worker showed me how to "cut across the hill" a few years back and it's still the most Pittsburgh thing I know how to do!