For me, the appeal of the Zebra F-301 Ultra ballpoint pen is all in the design.
The sleek stainless steel barrel, the encased no-nonsense clip, the grooved rubber grip. Some pens just look like they take writing very seriously, and the F-301 ballpoint is one of them. You pull one out of your pocket, and you're telling the world, 'I have important stuff to write down.'
You can't help but love a pen like that.
It also helps that these relatively inexpensive pens (less than £3) are so solidly made that they are recommended by the tactical pen crowd for self-defense. Yep, a pen that costs about the same as a regular plastic pen is tough enough to be used to protect yourself from muggers and rampaging beasts.
Of course, the writing aspect of the pen is slightly less spectacular. It's a ballpoint, which means the ink is dull-ish and given to the usual skips and whatnot. The barrel also is a bit short and narrow for a completely comfortable grip, an absolute must for long writing sessions.
However, for a ballpoint, the F-301 is a fairly smooth writer that moves across the page with little resistance. Even better, Zebra offers the same pen in a much smoother version called the G-301 (but that's a review for another day).
Overall, it might not be the pen you use to help fuel your creativity, but it is a must-have for all serious penthusiasts who want a smart-looking utility pen for daily use.