We've got Missile Command, a classic and very fitting for Fallout. We've got "Red Scare" as a Donkey Kong clone, odd but welcome. What else could there be? Captain Cosmos as Space Invaders or Galaga? Pip-Boy munching dots in a maze as commie ghosts close in on him? T?les of Chivalrie Joust? Grognak the Barbarian in a CYOA Thy Dungeonman 3 type game? The possibilities are endless! How about Doom? It's not a computer unless it can run Doom.
On a side note, do you think adding new ones through modding will be possible? As far as I am aware no one has been able to mod new casino games into New Vegas, but the new mod tools and how these games are implimented may lend themselves to easier modding.