I've hacked Megaman Xtreme 1/2 (created a map viewer), Zelda Oracle of Ages and Seasons (created a level editor for these games), Dragon Warrior Monsters 2 (Created a map viewer), Pokemon Gold/Silver (JohtoMap), Pokemon Red/Blue (ClassicMap), Zelda Link's Awakening DX (Created a level editor, which was terrible. But then again, that was a long time ago), and created a tileset viewer for Wario Land 3 or whatever it's called and MegaMan V, both from request.