If you could keep/have only one...
In the time-honored tradition of preposterous impositions: you can have only ONE pen, or even pencil (yeah, I'm that inclusive). Which one will it be?
It can be any writing instrument you have, or wish you had.
You may even qualify your answer with "at the moment", "these days" or "right now".
Do you go with something practical or something that encapsulates your passion for fountain p--fiddlesticks--writing instruments?
Also you will still need something to write on, in that alternate reality with only one writing instrument. What is your one and only notebook?
For me, were the writing apocalypse to befall us today, the choice is clear:
My Rotring 1928, because it has something of every aspect I love about fountain pens, and my SuperBuch A5, because its awesome and I only cracked it open yesterday.
What would yours be?