Is it really a regular part of your workflow? How often are you unsubscribing from lists?
Maybe just archive them when you are in the middle of workflow, then have a weekly time when you work up filtering for the non-spam unwanted email you got that week.
The priority inbox feature seems like it was made for you as well.
there could be also some other mechanisms (filtering titles?) - come on, I'm sure there are solutions that won't require me to get through four separate screens and interrupt my workflow!