After much screwing around and avoiding them I finally beat The Legend of Zelda, Ultimate Ghosts 'n Goblins and PixelJunk Shooter 2. The two former required the use of gamefaqs.com, the latter required the use of an update which gave me a counter of how much treasure I had collected.
With this in mind I must select my new opponents. For the Playstations 3, I choose DeathSpank, the action game by Hothead. For the DS I choose Lunar Knights, from Kojima Productions. For the PSP I choose Metal Gear Solid: Peace Walker. Lastly, for the Wii I choose Super Paper Mario.