Man o Man, there are just so many great balls mentioned on here! For me it was this list:
Columbia: Cuda-C, Aftershock, or Lime green Messenger
Ebonite: The whole V-2 series, the Vortex or the Killer Instinct pearl
Hammer: The 3D Offset or the Blade series
Brunswick: Infernos, Zone HPD, and I loved the Rhinos and Quantums of course.
Track: That Freak series was pretty exceptional.
Storm: I loved the Agent series; the X-Factors; and the Thunder Road
R/G: I was new to this line back then......so it would have to be the Assassin.