are you able to say put in like 2-4 usb contollers and play multiplayer games with friends on a pc? when i say friends i mean those in the same room as you all using one machine (a pc in this case)
On mac: you can do that with 2 users, 1 computer, 1 screen.
Lego Star Wars I
Lego Star Wars II
Lord of the Rings
Those games should be available on PC too.
I don't know of any computer centric game that allows 4 players at the same time. You can always install emulators on your Mac or PC though (not sure if emulation would handle 4 concurrent users...).