c'mon murdock, step up to the plate!
Okay, okay.
I wouldn't mind seeing classic gaming at NDK. I do appreciate the classics and do remember the 30 lives code for Contra, although there was a time I could beat the game without the use of the code (back in my prime).
I do like big pimpin father remington's suggestion of old space shooters. I am a huge fan of the shmups.
For the Dreamcast, Power Stone and Soul Calibur. For some more obsure-ish titles (I'm thinking two or more players here), JoJo's Bizarre Adventure, Zombie Revenge, or Giga Wing.
For the Genesis, Streets of Rage 2 and Gunstar Heroes (both have two player modes).
For the SNES, other than Super Contra, there's Pocky & Rocky (which I *believe* had a two player mode (I don't exactly remember right off the top of my head).
I guess you could also include Playstation games as well (I'm talking about *PlayStation 1*, here). I guess you could break out stuff like the original Guilty Gear, Raiden Project, Rival Schools and of course, Super Puzzle Fighter II Turbo.
That's all I got right now.