Most people don’t realize the playstation has been emulated and you can download it for free and start playing old games that you have lying about. The 2 best ones are ePSXe and AdriPSX, i use both there are lots of plugins available for both emulators, which range from emulating joypads and graphics cards to online multiplay. Both emulators have not been updated since 2003 but have a big following and there are many forums dedicated to supporting them.
Epsxe PSX emulator for Windows and Linux is the most advanced emulator, with lot of features Force Feedback, Save State, ISO support, Netplay and great compatibility.
AdriPSX is another PSX emulator for windows only, it's very easy to use and highly configurable. Again good compatibility and has many plugins available