In order of least to most challenging (IMO anyway):
Golden Sun II: Defeated Dullahan. Technically this isn't so hard if you just grind on Wonder Birds. Back when I played it as a kid though...I felt like a superhero after doing it.
Bravely Default: Finished Boss Gauntlet in Chapter 8, in particular, the magic user fight. I had a friend playing it at the same time, who managed to win by timing the turns and using the Stillness move. I was determined not to win with something that boring, so I ended up using a combination of Sword Magic and Ninja moves. I guess it's not so hard once you figure out a strategy...but it felt super satisfying completing it.
Pokemon: Heartgold - Beat Red. No trades...no hacks. Just grinding...so much grinding. Non-stop grinding. It never ends. *cries*
Fire Emblem: Rekka no Ken (Fire Emblem GBA): Beat Hector Hard Mode with no casualties and all side chapters unlocked. Enough said...*shivers*
NNID: Zephyr25 / PSN: Zephyr--25 / Switch: SW-4450-3680-7334
