Pilot Coleto - multicolor pen

These highly customizable pens are reliable and smooth (except for the dry 0.4mm red one in the video because I hadn't used it in a long while). They go through ink a little quicker than you'd expect, a lot due to the fact that those very thin refills simply don't hold much ink. But that means you get to buy new ones often and sample the many, many colors available. If you can easily get these at a local stationery store or online, they're fun to mix and match and ideal for taking notes. I wish they had been available when I was in school.