Well, this is a statement that will likely be met with scorn, derision and possibly pitchfork and torch wielding mobs, but I dislike Fisher space pens. Every full sized Fisher refill I've used for any length of time has leaked out big gobs of ink from the tip. Don't know why, either. The smaller refills for multipens I've had no such problems - I use one in my Inka pen.
For me, a good roller ball is my number one - a Rotring Freeway with a Pilot G2 fine point refill. German made, solid aluminum, I've had it for nearly 10 years and it looks as good as they day I got the pen off of eBay for $10. I used it to sign every sales and investment contract I've done for the last 7 years.