After the SNES thread like this, I thought it might be more interesting to discuss an older, less refined system to discuss games that hold up well. Sure games that you still enjoy due to nostalgia, but more importantly games you'd recommend to someone today who's never played them that you believe would make a believer out of them.
The biggest for me is Warlords. I get that game out at parties and it becomes the party. Everyone gradually makes their way over to see what all the noise is about, and it ends up with a crowd waiting to play and enjoying watching.
Another is Track & Field. It has surprisingly good graphics for a 2600 game, and the special controller gets the kind of button mashing fervor that the arcade cabinet does.
What are some others that are timeless and break through their limitations with a pure, outstanding experience?