Quoted from WaddleJrJr:
I don't know about actors (certainly something I'm interested to know though, and what I thought was the question when I clicked this thread), but at least as far as musicians go, Slash owns 4 pins, at one point owned much more (around 20 I think). Also Ed Robertson owns a pretty good bit, somewhere in the 10 - 20 range.
For musicians, Ryan Adams has them beat with 120+ pins:
"Located just a couple miles from the studio, Adams has a 3,500-square-foot warehouse, a former custom car shop that he’s converted into a private arcade. He’s been buying pinball machines, repairing and restoring them, for the past few years. His collection now numbers 120-plus vintage machines — from rock-themed games featuring The Rolling Stones to sci-fi favorites like Stargate, as well as a pair dedicated to horror hostess Elvira (a friend who appears in the video for the new album's first single, "Gimme Something Good"). “And I found the Holy Grail: Krull,” enthuses Adams. “It’s one of only nine machines ever made.”