I use: Emacs for editing/coding, mail, chat, task management, and calendar; Terminal for file system manipulation; Safari for browsing, though Chrome is nice too; Preview seems fine for PDFs.
Not much else on a daily basis.
Not much else on a daily basis.
The point of OSX, to me, is that it's a Unix which generally just works and has an interface worth using.
Oh, and it has a thriving and high-quality indie community.