I don't have anything crazy old probably my 900 global break s75, I can speak for a guy on my Monday scratch league he is averaging 230 with a black ice battle zone.

X Factor

I have a Ebonite Clear Wolf from 1996. Best spare/burnt lane ball ever.

It depends on the night &/or pattern if known ahead of time... But X-Factor on occasion but original Shift most times.

I still use my original Blue Vibe. I've had it for 6+ years, a few resurfaces, a couple oil extractions and it still moves the same it did when I first got it. It always seems like I can throw it when nothing else works and start stringing strikes

Visionary Slate Blue Gargoyle ,Ebonite Tornado, and Black Widow Bite.

On a regular basis I still use a pair of 1997 Visionary Blue Warlocks.  One is drilled 2 inch pin to PAP for tournament or sport patterns.  As far as I can tell, they don't appear to have lost much, if any, hook. 

I have been using them much more this season than in past seasons because our house is rotating between four different patterns and even though they are supposed to be adhering to a schedule of which pattern to lay down, due to maintenance issues with the lane machine or to the mechanics not knowing which button to push or the schedule, you never really know which pattern is out there until you bowl.  The Blue Warlock has always been a reliable benchmark ball for me so I end up using it more often than not.