I built a paper planner around David Allen's Paper Planner article. I use a Franklin Covey "classic" sized planner (5.5" by 8.5") which lets me take a normal sheet of paper and cut it in half. I bought the hole punch as well.

For me, this is a good complete system. It has all of my action lists, project lists, someday maybe lists, waiting for lists, agendas, a full year calendar, and a tabbed address book. Since it's loose leaf, it lets me move pages around and archive pages in a separate large ringed binder.

Here are my templates:

http://mikeshea.net/gtd_classic_planner.pdf

I built another binder for my mother for her new job. For her, we got a letter sized three-ring binder and I made templates for that based on mine:

http://mikeshea.net/gtd_full_planner.pdf

I'm sort of jealous of hers, although its a lot bigger.

For my system, my inbox is a Moleskine that I can carry all the time. My binder holds everything else. That way, at the very least, I have a way to capture new things even if I don't have all my other information.

Any smaller planner that didn't hold a full-year calendar and a complete address book just didn't have all of the things I needed in a single complete system.

If I can find the right one, I might switch to a full-sized planner, but for now, my Franklin Covey system does the job perfectly.