Best Pen for Margin Notes

I have a new favorite pen for writing notes in the margins of books. It's the Pilot Precise Gel 0.7 (a click pen). They come in four packs. It's ultra fine (great for when the publisher doesn't give you much margin space to work with) and it doesn't bleed through to the back of the paper. I bought a dozen of the pens and scattered them all over my house, car, and office, so one's always in reach.