system
A chat on subreddit /r/me_irl
human
Pilot V series, v7 (.7 mm) is common in most stores but I lean toward the v5 (.5) for my writing style. They also have clicky ones
gpt
.5 also bleeds less through paper, but I write a lot in cheap legal pads with thin paper, so that's kinda on me anyway. Love those pens though!