Pardon me if someone mentioned this already, but definitely Atomic Bomberman. It supports up to ten people on one frenzied playfield. Four friends and I had a blast with this one last weekend. Unfortunately, the sixth person had to leave, so no six-person bomber-fest, yet. I also really enjoy the SuperNES versions of bomberman, but you're limited to four or five players, the game seems slower and uses four buttons instead of the two that are needed for Atomic Bomberman. Super NES versions are good for nostalgia purposes, though. I learned about this game (also known as Bomberman 95) from a German friend who said he played it all the time with his grad student buddies. This is one of the few games I've noticed that can draw all ages. It's simple without insulting the older folk's intelligence.
One drawback for cab play is that only two players can use the keyboard and you pretty much need the escape button for exiting (I think you can use the gamepads instead of the "enter button" for setting up the game). Also, there are some great sounds and animations of trapped players digging their own graves, holding up signs a la Wil E. Coyote (sp?). Give it a go, probably can find your backup copy online somewhere, 50 megs or so.
Cheers,
KenToad