I've been using generic furniture movers (floor sliders), like the kind they sell in 8 packs at Home Depot. They're plastic on the bottom, and foam on the top.
My use case is this: I have games at a barcade with wood floors. The barcade has a stage where DJs play on the weekend. Two games stay on the stage during the week (because they help draw people into the pinball room, which is otherwise not obvious). On Friday night, the staff slides them off-stage into the side room with the rest of the machines, and then they are slid back to the stage on Sunday.
The sliders I buy work great the first few times, but after a few weeks they get scratched and worn, and they don't slide smoothly anymore. You can still push the machines, but the legs skid violently as this happens (which is loud and probably not great for the machines). The floors are wood and have a medium level of wear, and are probably not super clean all the time.
One small caveat is that there is only a few inches clearance under the doorway (so games with toppers can't be on stage).
Ideally, I'd like for the chosen sliding device to be able to live on the machine full time, so the game can be played without having to remove them.
Below is what I have now. Is there something better I could be using?