I'm not sure off the top of my head. It would likely come down to either one of the Zelda collections on the GameCube, or my black label copy of Castlevania: SotN, none of which I believe to be really rare. There's a slim chance I could have a rare NES game and I just don't know about it since I have a shit-ton of those.
The spawns can be shit, especially on Highjack, but with the levels being so small it's got to be hard to find an area with enough distance away from all the enemy players to safely spawn. As someone mentioned they are monitoring situations where you die within seconds of spawning, hopefully it will help but I can only see it making a marginal improvement.