I use a Staedtler Mars Pro with a 0.25 tip. I also use Sakura Pigma pens in various sizes. The only thing I put significant money into is the writing surface, which is a Moleskine Journal book. It has got smooth paper that doesn't bleed through, and a nice cover that makes it easy to write anywhere and keep my notes protected.
I used to have a Rapidograph 0.01, and I shudder to think of y'all refilling/cleaning those fountain pens. Nothing I ever want to go through again. Pressurised cartridges and porous nib fan here
