Mist Dragon, the Baron Guards, Octomammoth (well, except for Rydia dying), Scarmiglione's first form, Cagnazzo, Dark Elf's first form, Barbarrica (since I never got a Game Over facing her), Golbez (the very first time I barely defeated him though, since only Cecil was alive), Dr. Lugae (both forms), Leviathan, Demon Wall (I've never gotten a Game Over facing him), The Combined Elemental Lords, the CPU (first time it took a while figuring out how to beat him), the White Dragon, Lunasaurs, Dark Bahamut (I've never gotten a Game Over facing him, but it came close at times with over half my team dead), and that's all I can recall.