I have to admit it, I'm addicted to wearing headphones while playing pinball!
I take them with me when going to the arcade, I skip games that dont have headphone jacks.
Im so used to hearing all that the game has to offer, that I just dont enjoy the roar of the arcade any more.
Especially at $1 a game.

I added phone jacks to all of my pins.

In my own home when all my pins are being played, everyone enjoys the headphones.
I think it really improves my game as I can hear the call-outs better.

Saying all of this:

I have 10 pins set up and 10 headphones.
I chose the Sennheiser 201/202 headphones due to the relative low cost and excellent quality sound, and very good durability (except for thin cheap wires...) for a pinball machine.
https://www.amazon.com/gp/product/B003LPTAYI/ref=oh_aui_detailpage_o00_s00

What are others using and what do you think of my choice?