The most cost effective at the moment are gen2's. There's also a Gen2 Universal that will work. When buying a printer, you have to make sure you get one that has the firmware that is specific to your machine type. S2000's use netplex, so make sure you get a printer with the netplex plug and with IGT firmware, and if your machine does not have the printer brackets, make sure you get the printer brackets to mount it inside the box as well as the player tracking bar that is the correct size to allow for the printer to fit.