take the good with the bad.  some people just don't even want to play games.  I have arcade games and a 10 xbox 360/10 tv setup, along with a wii/ps3.  with that much variety usually someone is familiar with some of it.  you just never know.  I had some people out saturday and had nba jam going on my 4p mame cab and that got a fair amount of play.  along with the x360 cab I have super street fighter 4 in.  sometimes it's tough to find something that can keep the attention of 10 people on the xbox setup.  it just depends on the crowd.  i had 4p tetris on the wii and that got a fair amount of play.  i just suggest variety.  next party I plan on throwing is just after the release of gears 3, so I'm hoping to get 9 more people who are into that game out and it will be a good time. 
knock on wood, i've yet to have an arcade or mame cab fail on me yet during a party but I've had some xbox 360s fail, but that hardware is garbage, especially the old ones, so I have a few spares on hand.