My impression is that the best choice for 8-way is the competition joystick... It's purely an 8-way.
The Super joystick (I have 4 of them) are what I purchased. It was what the HotRod used, and that was the only reason I went with them. They're great (then again I haven't tried the competition... I would have gone with those had I known.) The Super has the benefit that you can switch some parts around and turn it into a 4-way. It's a pain in the butt to switch it around, and when you make it a 4-way, it's better than using an 8-way, but I don't think it's nearly as good as using a real 4-way. I think that when it's made to work as both, it suffers a trade-off of not being perfect for either (although it's clearly built to work best as an 8-way, and it works great as far as I'm concerned as an 8-way).
I read that the above two choices are better than the Ultimate.
Here's a link to pages on this website with reviews:
http://www.arcadecontrols.com/arcade_controls.shtml#JoysticksHere are some other (conveniently conflicting) things people have said on the net:
"Comments on the BYOAC Forum clearly indicate that HAPP Super joysticks are the best all-round control. They even work quite well for 4-way games, whereas many 8-ways tend to give false 4-way inputs. The HAPP Ultimate joysticks are apparently far from being