Yep. I have a PSJoy adaptor bought from the Zophar's Domain store when it was still in business. I use it for a playstation emulator, and PSX/PS2 ports on PC. It doesn't support rumble in Windows XP, but I have learned to live without it. It does the job just fine for playing PSX games though.
You can also get GCN - PC, SNES - PC, N64 - PC, if you are in need of a good controller, and even an Xbox - PC adaptor if you are masochistic.