I accidentally had a retro party once when I was in college. It was my birthday, so I took my hard-earned monies to the grocery store and bought a lot of booze thinking that'd be enough for a party. I think I also bought some Triscuits or something like that. Veggie cream cheese spread to go with it, perhaps. Anyway, later that evening, people came over and we were having a pretty decent time hanging out. At one point I mentioned I had a Sega Dreamcast and a NesterDC disc with around 500-600 games. I also had a gigantic, ancient, Sony front-projection TV where we could play it. The thing looked like you could open it up to melt Nazis if you wanted. It was old. So yeah, an instant retro-gaming (albeit with the help of an emulator) broke out on my birthday. It was great. I am not much of a host, so I was glad the Dreamcast was there to be my wingman that evening. Now that I have a quality collection of real retro games, I could host a proper party at some point. In retrospect, I wished I'd have spent that money on some pizzas or soda. People had such a great time rediscovering some of their old favorites.
rmaerz, that does sound like a kick ass retro gaming party. I think you have pretty good coverage in the video game department, so my only suggestion is to make sure you have plenty of salsa. I have found that those Scoopables chips tend to make the salsa well run dry much faster than intended.