For me, BBEdit is one of those applications that I just have too much time invested in. What it does is rather simple, and there are dozens of similar apps out there that accomplish the same thing. But having used BBEdit for so long, exclusively -- it's like an old baseball cap that fits just perfectly after years of wear. It's just comfortable.
That said, I finally upgraded to version 8.0 and have found the single feature that made it worth the purchase: the Documents Drawer. Instead of having multiple windows (one for each file) scattered all over the desktop, they're now contained in a single window. Toggling between or closing each file is handled in the new drawer that sticks off the side. This is good.
Now, I know what most of you are saying -- this feature is in every other text editor out there. And it probably is. Nothing ground-breaking being introduced here. But if you're a BBEdit user, there is reason for celebration.
I'm sure there are many other new features to be discovered, but this one makes it worth the upgrade alone.