Columbia:
-Black Knight (dry to medium oily conditions)
-Black U Dot (oily to medium conditions)
-Red U Dot (medium to oily conditions)
-Blue Dot (dry conditions)
Hammer:
-Blue Pearl (all conditions, except super oily and super dry)
-Black (medium to heavy conditions)
Brunswick:
Black Beauty (medium dry to medium oily conditions)
LT-48 (medium to oily conditions)
Black Rhino (medium to oily conditions)
AMF:
Black Angle (medium to oily conditions)
Loved every single one of those balls, but if I had to choose one, it would likely be the Blue Pearl Hammer, since I could play it on just about any condition, and it was a ball that always hit hard, whether the lanes were oily or on the drier side. I still have 2 in my collection.
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Regards,
BowlingWolf